BERKELEY 

{  LIBRARY   \ 

UNIVERSITY  OF 
CALIFORNIA 


EARTH 

SCIENCES 

LIBRARY 


Charles  If^ii,  Skinner 


a.  0.  Noun. 


IN  MEMORIAL 
Arthur     Eaton 


T1IK 


WONDERS    OF    GEOLOGY; 


GIDEON  ALGERNON  MANTELL,  LL.D.  F.R.S. 


IUTHOR  OP 


Silver  Coin*  of  Edward  the  First,  in  ironitone.—Page  67. 


EDITED  BY  PROFESSOR  SILLIMAN, 

WITH  AN  INTRODUCTION. 

IN    TWO   VOLUMES. 
VOL.  I. 

FIRST  AMERICAN,  FROM  THE  THIRD  LONDON  EDITION. 

A.  H.  MALTBY,  NEWHAVEN,  CONNECTICUT; 
RELFE  AND  FLETCHER,  LONDON. 

1839. 


THE 


WONDERS    OF    GEOLOGY; 


GIDEON  ALGERNON  MANTELL,  LL.D.  F.R.S. 


THE  G:  OLOOY  OV  THE  SOUTH  EAST  OF  ENGLAND, 
ETC.  ETC. 


Silver  Coin*  of  Edward  the  First,  in  ironttone.—1'nu''  I'.". 


"  To  tha  natural  philosopher  there  is  no  natural  object  unimportant 
or  trifling  :  from  the  least  of  nature's  works  he  may  learn  the  greatest 
lessons."— SIB  J.  F.  W.  HERSCHEL. 

"We  know  not  a  millionth  part  of  the  wonders  of  this  beautiful 
world." — LEIGH  HUNT. 


IN    TWO   VOLUMES. 
VOL.  I. 

FIRST  AMERICAN,  FROM  THE  THIRD  LONDON  EDITION. 


A.  H.  MALTBY,  NEWHAVEN,  CONNECTICUT; 
RELFE  AND  FLETCHER,  LONDON. 

1839. 


ENTERED 
According  to  the  Act  of  Congress  in  the  year  1839, 

BY  A.  H.  MALTBY, 
In  the  Clerk's  Office  of  the  District  of  Connecticut. 


LONDON : 
RICHARD   CLAY,    PRINTER,    BREAD    STREET    HILL. 


THE 

WONDEES   OF   GEOLOGY ; 

OR, 

A  FAMILIAR  EXPOSITION 
OF 

GEOLOGICAL  PHENOMENA  ; 

BEING  THE  SUBSTANCE  OF  A  COURSE  OF  LECTURES 
DELIVERED  AT  BRIGHTON. 

BY 

GIDEON  ALGERNON  MANTELL,  LL.D.  F.R.S. 

FELLOW  OP   THE   ROYAL   COLLEGE    OF   SURGEONS; 


CORNWALL  I 


F   THE   ACADEMIES   OF    NATURAL   SCIENCES   OF   PHILADELPHIA;  AND   OF   ARTS   AN 
SCIENCES   OF   CONNECTICUT;  OF   THE   GEOLOGICAL   SOCIETY   OF   PENNSYLVANIA; 

OF   THB   PHILOSOPHICAL  INSTITUTION   OF   BOSTON; 

OF  THE    HISTORICAL   SOCIETY    OF   QUEBEC;  AND   OF   THE    PHILOSOPHICAL 
SOCIETIES  OF    YORK,    NEWCASTLE,    ETC. 


"  Horum  conternplatio  multiplicem  habct  usutn.  Sunt  instar  nummoruni 
mernorialium,  quae  de  preteritis  globi  nostri  fatis  testantur,  ubi  omnia 
silent  monumcnta  historica." — BERGMAN.  Med.  de  Syst.  Fast. 


IN    TWO  VOLUMES. 
VOL.  I. 

FIRST  AMERICAN,  FROM  THE  THIRD  LONDON  EDITION. 

A.  H.  MALTBY,  NEWHAVEN,  CONNECTICUT; 
RELFE  AND  FLETCHER,  LONDON. 

1839. 


v.l 


EARTH 

SCIENCES 

LIBRARY 


BENJAMIN   SILLIMAN,   ESQ.    LL.D.    M.D. 

PROFESSOR    OF    CHEMISTRY    AND    OF    MINERALOGY 
IN    YALE   COLLEGE; 

EDITOR    OF    THE    AMERICAN    JOURNAL    OF    SCIENCE  ; 
FOREIGN    MEMBER    OF    THE    GEOLOGICAL    SOCIETY    OF    LONDON, 

:&c.  &c. 


OF 

THE     WONDERS     OF     GEOLOGY" 

IS  DEDICATED, 
IN     TESTIMONY     OF    THE     HIGH     RESPECT, 

AND  AFFECTIONATE  REGARD, 
OF    HIS    MUCH    OBLIGED   FRIEND,' 

THE   AUTHOR. 


CRESCENT  LODGE,  CLAPHAM  COMMON, 

SURREY,  ENGLAND. 

MAY  1,  1839. 


690899 


PREFACE. 


IN  preparing  the  first  edition  of  this  Work  for 
the  press,  I  was  greatly  assisted  by  the  kindness 
and  zeal  of  my  friend,  G.  F.  Richardson,  Esq.* 
whose  ability  as  a  reporter  enabled  him  to 
furnish  me  with  copious  notes  of  the  Lectures 
which  I  delivered  at  Brighton,  in  an  unsuc- 
cessful attempt  to  establish  a  County  Museum, 
and  Scientific  Institution  in  that  town.  Those 
notes  were  the  ground-work  of  the  unpretend- 
ing volumes  which,  under  the  title  of  "  THE 
WONDERS  OF  GEOLOGY,"  have  met  with  so 
favourable  a  reception. 

The  former  publication,  consisting  of  two 
thousand  copies,  having  been  disposed  of  in 
the  course  of  a  few  months,  a  new  edition  is 
required,  and  I  have  therefore  carefully  revised 

*  Of  the  British  Museum. 


viii  PREFACE. 

the  Work,  and  made  such  corrections  and 
additions  as  the  leisure  moments  which  my 
professional  engagements  have  allowed  me, 
would  permit. 

The  additional  illustrations  are  both  nume- 
rous and  important,  and  I  trust  will  be  found  to 
enhance  the  interest  of  these  volumes,  without 
having  materially  increased  their  size  or  price. 

My  geological  collection,  consisting  of  up- 
wards of  twenty  thousand  specimens,  from  which 
the  subjects  for  the  illustration  of  the  Lectures 
were  selected,  was,  at  the  period  of  the  former 
editions,  exhibited  at  Brighton  by  the  Sussex 
Literary  Institution,  as  the  "  Mantelllan  Mu- 
seum" At  that  time  I  had  every  reason  to 
believe  that  my  collection  would  be  permanently 
established  in  Sussex,  and  serve  as  the  foun- 
dation for  a  County  Museum.  In  that  expecta- 
tion I  have,  however,  been  utterly  disappointed ; 
for  although  I  would  willingly  have  made  any 
pecuniary  sacrifice,  to  accomplish  what  appeared 
to  me  so  desirable  an  object,  yet  after  the 
death  of  my  noble  and  lamented  friend,  the 
late  Earl  of  Egremont,  the  munificent  patron 
of  the  Institution,  the  proposed  measure  was 
abandoned,  and  even  opposed  by  many  of  its 


PREFACE. 


former  supporters.  T  have  therefore,  in  compli- 
ance with  the  wishes  of  my  scientific  friends, 
disposed  of  my  entire  collection  to  the  Trustees 
of  the  British  Museum. 

But  although  the  main  object  of  my  labours 
has  thus  been  frustrated,  and  that  collection, 
which  would  have  been  of  tenfold  importance 
if  located  in  the  district  from  whence  it  was 
derived,  and  whose  physical  structure  it  was 
designed  to  illustrate,  is  now  broken  up,  and 
will  be  dispersed  through  the  cabinets  of  our 
National  Institution,  yet  the  most  interesting 
specimens  are  so  unique,  and  so  strikingly  dis- 
tinct from  any  others  hitherto  obtained,  that 
they  may  be  referred  to  with  facility,  when  the 
gallery  of  organic  remains  in  the  British  Mu- 
seum shall  be  finally  arranged. 

I  avail  myself  of  this  means  to  record  the 
deep  sense  of  obligation  I  feel  to  many  ex- 
cellent friends,  for  their  strenuous  and  unre- 
mitting exertions  to  prevent  the  dispersion  of 
my  Museum,  and  establish  it  on  a  permanent 
basis  in  my  native  county.  And  although  their 
efforts  have  proved  unavailing,  a  time  will 
assuredly  come,  when  their  endeavours  to  pro- 
mote a  taste  for  scientific  knowledge  among 


x  PREFACE. 

the  intelligent  inhabitants  of  Sussex,  and  to 
direct  attention  to  the  investigation  of  its 
physical  phenomena,  will  be  properly  appre- 
ciated, and  the  failure  of  their  attempt  to 
secure  to  the  county  a  collection  so  rich  in  its 
peculiar  fossil  and  mineral  productions,  be  re- 
membered with  regret. 

Should  Providence  allot  me  life  and  health,  I 
purpose  adding  another  volume  to  this  Work, 
under  the  title  of  "  FIRST  LESSONS,  or  an  In- 
troduction to  THE  WONDERS  OF  GEOLOGY  ; " 
being  the  substance  of  a  series  of  Lectures, 
designed  for  persons  wholly  unacquainted  with 
the  nature  of  geological  investigations. 

G.  A.  M. 


CRESCENT  LODGE,  CLAPHAM  COMMON, 
May  1,  1839. 


TABLE    OF    CONTENTS. 
VOL.  I. 

LECTURE  I. 

Introductory  remarks.  2.  Importance  of  geology.  3.  Nature  of 
geology.  4.  Harmony  between  revelation  and  geology.  5.  Extent 
of  geological  epochs.  6.  Object  of  the  lectures.  7.  Physical  struc- 
ture of  the  earth.  8.  Geographical  distribution  of  animals  and 
vegetables.  9.  Temperature  of  the  earth.  10.  Nature  of  the  crust  of 
the  globe.  11.  Composition  of  the  rocks  and  strata.  12.  Classification 
of  rocks.  13.  Primary  rocks.  14.  Transition  strata.  15.  Secondary 
strata.  16.  Tertiary  strata.  17.  Alluvial  deposits.  18.  Geological 
mutations.  19.  Connexion  of  geology  with  astronomy.  20.  Nebular 
theory  of  the  universe.  21.  Different  states  of  nebulae.  22.  Formation 
of  the  solar  system.  23.  Gaseous  state  of  the  earth.  24.  Geology 
illustrated  by  astronomy.  25.  Meteorites.  26.  Mrs.  Somerville  on 
meteorites.  27.  Origin  of  meteorites.  28.  Existing  geological 
changes.  29.  Effects  of  streams  and  rivers.  30.  Delta  of  the  Ganges 
and  Mississippi.  31.  Formation  of  strata.  32.  Rippled  sand.  33. 
Lewes  levels.  34.  Remains  of  man  in  modern  alluvium.  35.  Peat 
bogs.  36.  Conversion  of  peat  into  coal.  37.  Subterranean  forests. 
38.  Geological  effects  of  the  sea.  39.  Bed  of  the  ocean.  40.  Currents 
and  their  effects.  41.  Incrusting  springs.  42.  Incrustations  not 
petrifactions.  43.  Lake  of  Solfatara.  44.  Marble  of  Tabreez.  45. 
Stalactites  and  stalagmites.  46.  Grotto  of  Antiparos.  47.  Consoli- 
dation of  sand  and  loose  materials.  48.  Destruction  of  rocks  by  carbonic 
acid.  49.  Carbonic  acid  gas  in  caverns  and  wells.  50.  Consolidation 
of  loose  strata  by  iron.  51.  Recent  formation  of  marine  limestone 
in  the  Bermudas.  52.  Fossil  human  skeletons  of  Guadaloupe.  53. 
Impressions  of  human  feet  in  sand-stone.  54.  Isle  of  Ascension. 
55.  Drifted  sand.  56.  Sand-flood  and  recent  limestones  of  Cornwall. 
57.  Silicious  deposits.  58.  The  Geysers.  59.  Hertfordshire  con- 
glomerate, or  pudding-stone.  60.  Effects  of  high  temperature.  61. 
Volcanic  agency.  62.  Expansion  of  rocks  by  heat.  63.  Temple  of 
Jupiter  Serapis.  64.  Elevation  of  the  coast  of  Chili.  65.  Lifted  sea 
beach  at  Brighton.  66.  Elevation  of  Scandinavia.  67.  Retro- 
spect   p.  l 


xii  TABLE  OF  CONTENTS. 


LECTURE  II. 

Introductory  observations.  2.  Extinction  of  animals.  3.  Animals 
extirpated  by  human  agency.  4.  The  apteryx  australis.  5.  The  dodo. 
6.  The  Irish  elk.  7.  Epoch  of  terrestrial  mammalia.  8.  Character 
of  the  ancient  alluvial  deposits.  9.  Classification  of  mammalian  re- 
mains. 10.  Comparative  anatomy.  11.  Adaptation  of  structure  in 
animals.  12.  Osteological  characters  of  the  carnivora.  13.  Structure 
of  the  herbivora.  14.  Structure  of  the  rodentia,  or  gnawers.  15. 
General  inferences.  16.  Fossil  bones.  17.  Fossil  elephants,  or  mam- 
moths. 18.  Mammoth  and  rhinoceros  in  ice.  19.  Teeth  of  recent, 
and  fossil  elephants.  20.  The  mastodon.  21.  Mastodons  from  the 
Burmese  empire.  22.  The  sivatherium.  23.  The  megatherium.  24. 
The  megalonyx.  25.  The  sloth.  26.  Fossil  hippopotamus,  rhinoceros, 
horse,  &c.  27.  The  dinotherium.  28.  Fossil  carnivora  in  caverns. 
29.  Cave  of  Gaylenreuth.  30.  Forster's  Hohle.  31.  Bone  caverns  in 
England. — Kirkdale  cave.  32.  Diseased  bones  of  carnivora  found 
in  caves.  33.  Human  bones,  and  works  of  art  in  caverns.  34.  Osseous 
breccia,  or  bone  conglomerates.  35.  The  rock  of  Gibraltar.  36.  Osseous 
breccia  of  Australia.  37.  Retrospect p.  113 


LECTURE  III. 

I.  Introductory  remarks.  2.  Substances  composing  the  crust  of  the 
globe.  3.  Crystallization.  4.  Stratification.  5.  Inclined  and  vertical 
strata.  6.  Veins  and  faults.  7.  Chronological  arrangement  of  the 
strata.  8.  Tertiary  formations.  9.  Classification  of  the  tertiary  strata. 
10.  Fossil  shells.  11.  Mineralogical  characters  of  the  tertiary  system. 
12.  Newer  tertiary  or  pliocene  deposits.  13.  Crag  of  Norfolk  and 
Suffolk.  14.  The  Sub-Apennines.  15.  Middle  tertiary,  or  miocene 
deposits.  16.  Lower  tertiary,  or  eocene  deposits.  17.  The  Paris  basin. 
18.  The  London  basin.  19.  The  Isle  of  Sheppey.  20.  Fossil  fruits  of 
the  tertiary  strata.  21.  Upper  marine,  or  Bagshot  sand.  22.  Artesian 
wells.  23.  The  Hampshire  or  Isle  of  Wight  basin.  24.  Alum  bay. 
25.  London  clay  of  the  Hampshire  basin.  26.  Fresh-water  strata  of  the 
Isle  of  Wight.  27.  Organic  remains  of  the  Paris,  London,  and  Hants 
basins.  28.  Fossil  plants  and  zoophytes.  29.  Tertiary  marine  and 
fresh-water  shells.  30.  Nummulites,  and  other  cephalopoda.  31.  Crus- 
tacea and  fishes.  32.  Fossil  birds.  33.  Fossil  animals  of  Paris.  34. 
Palaeotheria  and  anoplotheria.  35.  Fossil  quadrumana,  or  monkeys. 
36.  Tertiary  strata  of  Aix,  in  Provence.  37.  Fossil  insects.  38.  Lacus- 
trine formation  of  (Eningen.  39.  Fossil  fishes  of  Monte  Bolca.  40. 
Tertiary  volcanoes  of  France.  41.  Extinct  volcanoes  of  Auvergne. 


TABLE  OF  CONTENTS.  xiif 

42.  The  crater  of  Puy  de  Come.  43.  Mont  Dor.  44.  Fresh-water  lime- 
stone and  organic  remains  of  Auvergne.  45.  Summary  of  the  geological 
phenomena  of  Auvergne.  46.  Erosion  of  valleys  by  water-currents. 
47.  Extinct  volcanoes  of  the  Rhine.  48.  Brown  coal  formation.  49. 
Other  tertiary  strata  of  Europe,  North  America,  &c.  50.  Altered  ter- 
tiary strata  of  the  Andes.  51.  Tertiary  saliferous  deposit.  52.  Retro- 
spect. 53.  Concluding  remarks p.  184 


LECTURE  IV. 

Introductory  remarks.  2.  Secondary  formations.  3.  The  chalk  for- 
mation. 4.  Chalk  and  flint.  5.  Flint  nodules.  6.  Organic  remains 
in  flint.  7.  Sulphuret  of  iron.  8.  Maestricht  beds.  9.  St.  Peter's 
mountain.  10.  Mossesaurus  of  Maestricht.  11.  Lower  group  of  the 
chalk.  12.  Organic  remains  of  the  chalk.  13.  Fossil  vegetables. 
14.  Fossil  zoophytes.  15.  Radiaria  and  crinoidea.  16.  Echinites. 
17.  Shells  of  the  chalk.  18.  Cephalopoda.  19.  The  belemnite.  20. 
The  nautilus.  21.  The  ammonite,  or  cornu  ammonis.  22.  Turrilite, 
hamite,  &c.  23.  Spirolinites.  24.  Infusoria  in  flint.  25.  Crustacea 
of  the  chalk.  26.  Fishes  of  the  chalk— sharks.  27.  Fossil  salmon, 
or  smelt.  28.  Macropoma,  and  other  fishes  of  the  chalk.  29.  Reptiles 
of  the  chalk.  30.  Review  of  the  chalk  formation.  31.  Geology  of  the 
south-east  of  England.  32.  Geological  phenomena  between  London 
and  Brighton.  33.  The  wealden.  34.  Wealden  of  the  Sussex  coast. 
35.  Pounceford.  36.  Sub-division,  and  extent  of  the  wealden.  37. 
Quarries  of  Tilgate  forest.  38.  Rippled  sandstone.  39.  Wealden  of 
the  Isle  of  Wight.  40.  Isle  of  Purbeck.  41.  Petrified  forest  of  the 
Isle  of  Portland.  42.  Modern  submerged  forest.  43.  Fossils  of  the 
wealden.  44.  Fossil  vegetables— ferns.  45.  Clathraria  and  endo- 
genites.  46.  Seed-vessels.  47.  Fossil  shells.  48.  Sussex  marble. 
49.  Fossil  cypris.  50.  Fishes.  51.  Reptiles  of  Tilgate  forest.  52. 
Fossil  turtles.  53.  Fossil  crocodiles.  54.  The  Swanage  crocodile. 
55.  The  plesiosaurus.  56.  The  megalosaurus.  57.  The  iguanodon. 
58.  The  Maidstone  iguanodon.  59.  Size  of  the  iguanodon.  60.  The 
hylaeosaurus.  61.  Flying  reptiles.  62.  Fossil  birds.  63.  The  country 
of  the  iguanodon.  64.  Sequence  of  geological  changes.  65.  Retro- 
spect of  geological  mutations p.  287 

APPENDIX. 


TABLE    OF    CONTENTS. 
VOL.  IT. 

LECTURE  V. 

1.  The  zoological  character  of  the  chalk.  2.  Zoological  character  of  the 
wealden.  3.  Site  of  the  country  of  the  iguanodon.  4.  Medial  secon- 
dary formations.  5.  The  oolite,  or  Jura  limestone.  6.  Tabular  view 
of  the  oolite  and  lias.  7.  Geographical  distribution  of  the  oolite  and 
lias.  8.  Stonesfleld  slate.  9.  Organic  remains  of  the  Stonesfield 
slate.  10.  Fossil  opossum  of  Stonesfield.  11.  Wealden  and  Stones- 
field  fossils.  12.  Lithographic  slates  of  Pappenheim,  Solenhofen, 
andMonheim.  13.  Coal  of  the  oolite.  14.  Geographical  distribution 
of  the  lias.  15.  Organic  remains  of  the  oolite  and  lias.  16.  State  of 
fossilization.  17.  Saliferous,  or  new  red  sandstone  system.  18.  Tabular 
view  of  the  saliferous  system.  19.  Geographical  distribution  of  the 
saliferous  strata.  20.  Cheltenham  waters.  21.  Rock-salt  and  brine- 
springs.  22.  Magnesian  limestone,  or  zechstein.  23.  Conglomerates 
of  the  new  red  sandstone.  24.  Organic  remains  of  the  saliferous 
strata.  25.  The  spiriferae  of  the  new  red  sandstone.  26.  Impressions 
of  the  feet  of  animals  on  sandstone.  27.  Reptiles.  28.  Turtles. 
29.  Fossil  turtles.  30.  Crocodiles.  31.  The  ichthyosaurus.  32.  The 
plesiosaurus.  33.  Pterodactyles,  or  flying  reptiles.  34.  Fossil  sala- 
mander. 35.  Fossil  reptiles  allied  to  the  lizards.  36.  Review  of  the 
Age  of  reptiles.  37.  Objections  considered.  38.  Concluding  re- 
marks    P-  429 

LECTURE  VI. 

1.  Introductory  remarks.  2.  Organic  and  inorganic  kingdoms.  3.  Dis- 
tinctive characters  of  animals  and  vegetables.  4.  Nervous  system, 
and  sensation.  5.  Diversity  of  animal  forms.  6.  Ellis's  discoveries. 
7.  Nature  of  sponge.  8.  Cilia,  or  vibratile  organs.  9.  The  hydra,  or 
fresh-water  polype.  10.  Zoophytal  organization.  11.  The  food  of 
zoophytes.  12.  Mode  of  increase  and  death.  13.  Corals,  or  skeletons 
of  zoophytes.  14.  Diversity  of  form  and  structure.  15.  Geographical 
distribution  of  the  polyparia.  16.  The  flustra,  or  sea-mat.  17.  The 


TABLE  OF  CONTEXTS.  xv 

vesicular  corallines,  or  serttilariae.  18.  The  gorgonia,  or  sea-fan. 
19.  The  red  coral.  20.  The  tubipora,  or  organ-pipe  coral.  21.  Ma- 
drepores. 22.  The  actinia,  or  sea-anemone.  23.  Caryophyllia  and 
turbinoiia.  24.  Fungia.  25.  Astrea,  pavonia,  &c.  26.  Meandrina 
cerebrifovmis,  or  brain-coral.  27.  Appearance  of  the  living  corals. 
28.  Coiai  reel's.  29  Coral  reef  of  Loo  Choo.  30.  Coral  islands.  31. 
Fossil  zoophytes.  32.  Zoophytes  of  the  chalk.  33.  Zoophytes  of  the 
Shanklin  sand.  34.  Recent  formation  of  chalk  from  corals.  35.  Fossil 
infusoria.  3t>.  Corals  of  the  oolite  and  lias.  37.  Corals  of  the  older 
secondary  formations.  38.  Coralline  marbles.  39.  The  crinoidea,  or 
lily-shaped  animals.  40.  Encrinites  and  Pentacrinites.  41.  Struc- 
ture of  the  crinoiuea.  42.  The  lily  encrinite.  43.  Pear  encrinite  of 
Bradford.  44.  Pentacrinites,  actinocrinites,  and  other  crinoidea.  45. 
Derbyshire  encrinital  marble.  46.  Geological  distribution  of  the  cri- 
noidea. 47.  Concluding  remarks  p.  505 

LECTURE  VIT. 

Introductory  remarks.  2.  The  carboniferous  system.  3.  The  coal 
measures.  4.  Coal-field  of  Derbyshire.  5.  Coalbrook  dale.  6.  Coal- 
shales,  and  vegetable  remains.  7.  Carboniferous,  or  mountain  lime- 
stone. 8.  Derbyshire  lead  mines.  9.  Carboniferous  system  of 
Devonshire.  10.  The  Devonian  system,  or  old  red  sandstone.  11. 
Geographical  distribution  of  the  carboniferous  system.  12.  Volcanic 
rocks  of  the  carboniferous  system.  13.  Trap-dikes  of  the  carboni- 
ferous sjstem.  14.  Organic  remains  of  the  carboniferous  system. 
15.  Organization  of  vegetables.  1C.  Coniferous  trees.  17.  Climate 
and  seasons,  indicated  by  fossil  wood.  18.  Vertical  trees  in  carboni- 
ferous strata.  19.  Trunks  of  coniferae  in  Craigleith  quarry.  20. 
Microscopic  examination  of  fossil  trees.  21.  Nature  of  coal.  22. 
Mineral  oil,  naphtha,  and  petroleum.  23.  Bitumen,  amber,  and 
mellite.  24.  The  diamond.  25.  Anthracite,  cannel  coal,  and  plum- 
bago, or  graphite.  26.  Nature  of  petrifaction.  27.  Artificial  pe- 
trifactions. 28.  Different  states  of  the  fossilization  of  wood.  29. 
Hazel-nuts  filled  with  spar.  30.  Silicification,  or  petrifaction  by  silex. 
31.  Plants  in  agates,  &c.  32.  Plants  of  the  coal  formation .  33.  Fossil 
mare's-tail,  or  equisetum.  S4.  Fossil  ferns.  35.  Sigillariae,  or  fossil 
arborescent  ferns.  36.  Lepidodendron.  37.  Fossil  club-moss,  or 
lycopodites.  38.  Stigmaria.  39.  Seed-vessels  in  coal.  40.  Coniferae. 
41.  Review  of  the  carboniferous  flora.  42.  Formation  of  new  coal- 
measures.  43.  Corals  and  crinoidea  of  the  carboniferous  system. 
44.  Shells  of  the  carboniferous  system.  45.  Crustacea.  46.  The 
limulus,  or  king-crab.  47.  Trilobites.  48.  The  eyes  of  the  trilobite. 
49.  Insects  of  the  coal  formation.  50.  Fishes  of  the  carboniferous 
and  Devonian  systems.  51.  Retrospect— the  flora  of  the  ancient 
world P- 595. 


xvi  TABLE  OF  CONTENTS. 


LECTURE  VIII. 

Introductory  remarks.  2.  Silurian  and  Cambrian  systems.  3.  Silurian 
system.  4.  Cambrian,  or  slate  system.  5.  Structure  of  slate  rocks. 
6.  Organic  remains  of  the  Silurian  and  Cambrian  systems.  7.  Meta- 
morphic  character  of  slate  and  greywacke.  8.  Metamorphic  or  pri- 
mary rocks.  9.  Mica-schist  and  gneiss.  10.  Unstratified  metamorphic 
rocks— granite.  1 1 .  Volcanic  agency.  12.  Vesuvius.  13.  Eruptions 
of  Vesuvius.  14.  Volcanic  products  of  Vesuvius.  15.  Mount  Etna. 
16.  Phlegrean  fields,  and  the  Lipari  isles.  17.  Volcano  of  Kirauea— 
Hawaii.  18.  Stewart's  visit  to  Kirauea.  19.  Earthquakes.  20.  Vol- 
canic island  in  the  Mediterranean.  21.  Volcano  of  Jorullo,  in  Mexico. 
22.  Organic  remains  buried  beneath  lava.  23.  Ice  preserved  by  in- 
candescent lava.  24.  Herculaneum  and  Pompeii.  25.  Professor 
Silliman  on  geological  evidence.  26.  Basalt  or  trap.  27  Staffa — 
Fingal's  cave.  28.  The  Giants'  Causeway.  29.  Rocks  altered  by  con- 
tact with  basalt.  30.  Trap  dikes  and  veins.  31.  Strata  altered  by 
contact  with  metamorphic  rocks.  32.  Granite  veins.  33.  Metamorphic 
rocks.  34.  Metalliferous  veins.  35.  Copper  ore  of  New  Brunswick. 
36.  The  sapphire,  ruby,  and  emerald.  37.  Review  of  the  Silurian 
and  Cambrian  systems.  38.  Review  of  the  metamorphic  rocks.  31*. 
Organic  remains  (?)  in  the  metamorphic  rocks.  40.  Relative  age  of 
mountains.  41.  Successive  changes  in  the  organic  kingdoms.  42. 
Successive  development  of  the  organic  kingdoms.  43.  Geological 
effects  of  mechanical  and  chemical  action.  44.  Rocks  composed  of 
organic  remains.  45.  General  inferences.  46.  Final  causes.  47. 
Geological  theory  of  Leibnitz.  48.  Astronomical  relations  of  the  solar 
system.  49.  Concluding  remarks p.  692 

APPENDIX. 


PROFESSOR    SILLIMAN'S 
REMARKS 


INTRODUCTORY  TO  THE  FIRST  AMERICAN  EDITION 
OF 

DR.  MANTELL'S   WONDERS   OF  GEOLOGY. 


1.  OBJECT  OF  THE  SCIENCE. — Geology*  is  the  natural, 
history  of  the  earth.  Its  hills  and  mountains,  its  rivers, 
lakes,  seas,  and  oceans,  its  caverns  and  valleys,  its  fertile 
plains  and  sterile  deserts — in  a  word,  all  that  belongs  to 
physical  geography,  is  included  within  its  domain.  Inci- 
dentally, it  takes  notice  of  villages,  towns,  and  cities,  of 
works  of  art,  of  agriculture  and  commerce,  of  the  various 
improvements  of  civilization,  and  of  the  races  and  families 
of  animated  beings  of  both  organic  kingdoms,  since  they 
are  all  influenced  by  geological  causes,  and  affected,  more 
or  less,  by  geological  events,  while  they,  in  turn,  afford 
monumental  evidence  of  the  physical  history  of  the  globe. 
The  terrestrial  surface  sympathizes  with  the  profound  in- 
terior, and  its  physiognomy  is  often  changed  by  the  operation 
of  internal  causes ;  just  as  the  human  face  becomes  fallen 
and  pale,  or  full  and  glowing,  as  it  is  affected  either  inju- 
riously by  internal  disease,  or  cheered  by  the  health  of  the 
body.  Every  thing  upon  this  earth  is,  therefore,  more  or 
less  concerned  with  geology,  and  this  science,  in  turn, 

*  From  7»,  the  earth,  and  Xo-yor,  an  account  of. 
b 


--.• 


reviews  the  principal*  facts'  'and  events  (more  especially 
those  of  a  physical  nature)  of  which  this  planet  is  the 
theatre. 

But,  the  more  appropriate  object  of  geology  is  to  ascer- 
tain the  structure  of  the  earth,  and  to  deduce  from  the 
facts  a  legitimate  theory.  It  includes  a  knowledge  of  the 
masses  of  which  our  planet  is  composed — the  order  of  their 
arrangement — their  mineral  and  organic  contents — the 
proximate  causes  by  which  they  were  formed  and  depo- 
sited, and  those  by  which  they  are  rendered  liable  to  future 
changes. 

2.  PRELIMINARY  KNOWLEDGE. — These  considerations 
necessarily  involve  a  knowledge  of  physical  laws.  We 
must  be  acquainted  with  the  chemical  constitution  of 
matter,  with  the  combinations  its  elements  are  capable  of 
forming,  with  the  liabilities  of  the  compounds  to  form  new 
arrangements,  and  with  the  secret  laws  governing  these 
events.  The  mechanical  laws  must  also  be  kept  in  view ; 
the  weight  and  pressure  and  moving  power  of  both  solids 
and  fluids,  the  varieties  and  force  of  attraction ;  in  a  word, 
the  dynamics  of  our  globe.  Nor  can  it  be  considered 
entirely  apart  from  its  planetary  relations,  as  a  member  of 
the  solar  system,  and  of  the  innumerable  systems  which 
compose  the  stellar  universe.  Remotely  then,  but  still  dis- 
tinctly and  efficiently,  the  earth  must  be  viewed  in  its 
astronomical  connexion,  out  of  which  grow  important 
analogies  and  elucidations. 

Those  subtile  agents,  unknown  in  their  essence,  but  most 
manifest  and  potent  in  their  effects — namely,  heat,  light, 
electricity,  and  magnetism,  either  distinct,  or  combined  in 
various  modifications,  demand  a  faithful  study,  that  we 
may  comprehend  their  manifold  and  unceasing  effects  in 
the  economy  of  the  earth ;  nor  must  the  enveloping  ocean 
of  aerial  fluid,  the  atmosphere,  in  which  their  energy  is  so 
yften  displayed,  be  forgotten;  both  in  its  physical  and 


chemical  characters,  it  demands  our  attention.  We  must 
also  know  the  outlines  of  natural  history,  especially  of  the 
mineral  species,  or  at  least,  of  those  which  are,  or  have 
been,  chiefly  concerned  in  producing,  by  their  extension  or 
aggregation,  the  mountains  and  continents,  and  the  entire 
planet,  so  far  as  it  is  cognizable  by  man.  A  competent 
knowledge  of  mineralogy  ought,  therefore,  to  precede  the 
study  of  geology ;  it  is  true,  we  may  begin  with  a  com- 
paratively small  number  of  the  most  important  minerals, 
as  our  increasing  acquaintance  with  rocks  will  constantly 
augment  our  familiarity  witli  mineral  species. 

In  like  manner,  as  mineralogy  is  indispensable  to  the 
study  of  geology,  so  the  other  departments  of  natural 
history  are  auxiliary  to  it,  in  a  most  important  degree. 
Animals  and  plants,  either  entire  or  dismembered,  or  in 
fragments  and  ruins,  are  involved  in  almost  all  classes  of 
rocks,  except  the  primary  and  the  volcanic ;  nor  can  we 
assign  the  limit  of  organic  matter  even  in  these,  for  we 
know  not  how  far  fire,  by  softening  or  fusion,  may  have 
obliterated  the  organic  remains  that  might  once  have  been 
blended  with  materials  now  exhibiting  no  vestige  of  plants 
or  animals.  Although  we  may  not  be  able  to  mark  the 
precise  boundary  beyond  which  organic  beings  do  not 
appear,  it  is  certain  that  in  all  geological  epochs,  subse- 
quent, at  least,  to  that  of  the  primary  rocks,  animals  and 
plants  have  existed  in  successive  families ;  they  have  been 
created,  have  lived  their  day,  and  by  the  operation  of 
physical  causes,  have  perished ;  while  new  races  have  been 
called  into  being,  and  in  their  turn  have  ceased  to  be,  in 
order  to  give  room  to  other  families,  requiring,  perhaps,  a 
different  climate,  and  a  new  order  of  things. 

Thus  we  travel  onward  in  time,  and  upward  in  the  order 
of  deposition,  through  races  whose  species  are  entirely  ex- 
tinct, until  we  arrive  at  the  periods  that  approximate  to  our 
own  times,  when  first,  similar  beings  to  those  that  now 
62 


inhabit  the  earth  begin  to  appear,  and  finally  to  graduate 
into  those  of  the  present  day.  Now  it  is  obvious,  that  to 
judge  intelligently  of  extinct  races  of  beings,  once  endowed 
with  animal  or  vegetable  life,  it  is  requisite  to  pass  in 
review  the  entire  organic  creation,  both  of  ancient  and  mo- 
dern date ;  not  only  of  the  terrestrial  animals  that,  in  early 
time,  walked  the  earth,  of  the  fishes  or  amphibia  that  swam 
in  its  waters,  of  the  birds,  insects,  and  winged  reptiles,  that 
soared  in  the  air,  and  of  plants  that  adorned  its  new-born 
islands  and  emerging  continents,  and  which,  as  well  as  the 
animals,  are  now  entombed  in  rocks  and  mountains ;  but 
we  must  be  familiar,  also,  with  the  races  which,  at  this 
moment,  fill  the  world  with  animation  and  beauty,  for  they 
are  our  living  standards  of  comparison.  In  short,  we  must 
be  well  acquainted  with  both  natural  history  and  con^ra- 
tive  anatomy. 

If  such  be  the  circle  of  sciences  preliminary  or  auxiliary 
to  geology,  it  may  well  draw  from  us  the  desponding  ex- 
clamation, Who  then  is  sufficient  for  these  things?  We 
may  perhaps  reply,  no  unassisted  individual !  Science  is 
formed  by  the  joint  labours  of  many  minds.  Different  cul- 
tivators bring  in  the  rich  tribute  of  the  fields  they  have 
tilled  and  reaped,  and  a  master-mind  disposes  them  in 
order,  and  draws  from  them  the  requisite  resources,  to 
construct  a  system,  or  at  least,  to  furnish  its  most  impor- 
tant elements. 

3.  RANK  AMONG  THE  SCIENCES.  —  This  very  general 
sketch  of  the  relations  which  geology  sustains  to  the  colla- 
teral sciences,  is  sufficient  to  evince  its  high  importance, 
and  to  vindicate  its  strong  claims  to  our  warm  regard. 

As  a  science,  it  is  true,  its  date  is  modern;*  but  this  is 

*  Mr.  Lyell,  in  the  historical  introduction  to  his  Principles  of  Geology, 
lias,  however,  cited  a  number  of  early  authors  who  have  expressed  just 
views,  and  pointed  out,  at  least  to  a  certain  extent,  the  proper  course  to 
be  pursued. 


also  the  case  with  all  the  physical  sciences,  among  which 
geology  is  a  younger  sister.  Although  it  is  rapidly 
advancing,  and  is,  therefore,  not  perfect,  it  is  still  a  science ; 
and  in  this  sense,  which  of  the  phj^sical  sciences  is  perfect? 
A  few  hundred  years  will  include  the  dates  of  most  of  them, 
while  all  are  still  advancing,  and  will  continue  to  advance. 
In  this  respect  geology  is,  therefore,  not  alone.  Its  ascer- 
tained facts  are  numerous ;  they  are  correctly  observed  and 
reported ;  they  are  skilfully  classed,  anda  a  sufficient  num- 
ber of  general  as  well  as  particular  conclusions  has  been 
drawn  from  them  to  furnish  the  basis  of  a  noble  science. 
Its  boundaries  are  daily  extending,  and  will  be  extended 
without  limit,  by  continued  observations — its  evidence  will 
conjointly  accumulate,  and  although  its  theoretical  specu- 
latwfcs  may  change,  nothing  can  occur  to  subvert  the  grand 
conclusion,  that  the  earth  has  a  regular  structure,  and  that 
its  materials  have  been  arranged  under  the  operation  of 
general  and  immutable  laws,  the  physical  expression  of 
omniscient  intelligence,  and  omnipotent  sway,  guided  by 
benevolent  design,  which  becomes  more  and  more  apparent 
and  convincing  with  every  new  and  successful  research  in 
geology. 

4.  SOURCES  OF  ITS  EVIDENCE. — If  the  inquirer  asks  for 
the  source  of  geological  evidence,  it  may  be  answered  that 
it  is  derived  from  diligent  and  careful  examination  of  the 
structure  of  the  earth,  and  for  this  object  our  means  are 
more  ample  than  might  at  first  appear. 

Every  artificial  excavation — every  well  and  cellar — every 
cut  for  a  fort,  common  road,  railway,  or  canal — every 
quarry — every  tunnel  through  a  mountain — and  every 
pit  and  gallery  of  a  mine  bored  into  the  solid  earth, 
furnish  means  of  investigating  its  interior.  Still  more 
do  the  inland  precipices,  and  the  rocky  promontories  and 
headlands  along  the  rivers,  lakes,  seas,  and  oceans; 
the  naked  mountain-sides  ribbed  with  strata,  that  bound 


6 

the  defiles,  gorges,  and  valleys ;  the  ruins  accumulated  at 
the  feet  of  lofty  pinnacles  and  harriers,  and  those  that  have 
been  transported  and  scattered,  far  and  wide,  over  the 
earth;  present  us  with  striking  features  of  the  internal 
structure  of  our  planet.  Most  of  all,  do  the  inclined  strata 
push  up  their  hard  edges,  in  varied  succession,  and  thus 
faithfully  disclose  the  form  and  substance  of  the  deep  in- 
terior, as  it  exists  many  miles  and  leagues  beneath  the 
observer's  feet. 

Volcanic  eruptions  elevate  the  foundations  of  the  fathom- 
less deep  below,  either  in  the  form  of  ejected  or  molten 
masses;  or  in  rivers  of  ignited  and  fluid  rocks,  which 
congeal  on  the  surface  of  the  ground,  either  inflated  like 
the  scoriae  of  furnaces,  or  in  solid  forms,  with  no  visible 
impress  of  heat,  and  often  containing  very  perfect^  and 
beautiful  minerals,  conceived  in  the  volcano;  or  dislodged 
from  still  earlier  beds,  from  a  more  profound  igneous  abyss, 
and  urged  along  by  the  irresistible  current  which  often 
ruptures  the  crust  of  the  earth,  and  covers  it  with  a  fiery 
deluge.  In  addition  to  the  products  of  actual  volcanoes — 
the  ignigenous  rocks,  crystallized  or  deposited  from  fusion 
— both  in  the  earliest  and  in  many  of  the  more  modern 
epochs — injected  among,  and  cutting  across  strata  of  almost 
all  descriptions  and  ages,  and  thus  assimilated  to  known 
products  of  internal  fire;  the  proper  rocky  masses — the 
granites — the  sienites — the  porphyries — the  serpentines  and 
the  traps,  give  authentic  information  of  the  unapproachable 
gulf  of  fire  whence  they  were  projected. 

The  internal  waters  that  gush  cool  from  the  fountains  on 
land  or  under  the  sea,  or  those  that  spout  in  boiling  geysers 
from  the  deep  caverns  where  their  imprisoned  vapours 
accumulate  explosive  force ;  all  these  bring  to  the  surface 
the  materials  of  the  interior,  and  conspire  with  tornadoes 
of  gas,  bursting  from  volcanoes  and  other  vents,  to  reveal 
the  deep  secrets  of  the  earth. 


5.  ITS  POSITIVE  UTILITY. — Geology,  in  addition  to  its 
inherent  dignity,  puts  forth  strong  claims  to  regard  on  the 
ground  of  positive  utility.  Every  thing  reposes  upon  the 
mineral  kingdom.  This  earth  affords  to  man,  directly  or 
indirectly,  all  the  materials  of  his  physical  comfort — all 
those  of  national  wealth,  and  all  the  means  of  civilization. 
A  mere  savage,  ignorant  and  brutal,  and  the  creature  of 
appetite  alone,  can  never  rise  from  his  degradation,  until 
he  has  learned  to  draw  from  the  mineral  kingdom  the 
instruments  of  arts  and  civilization,  or,  at  least,  to  use  the 
aids  that  are  thus  obtained.  The  axe,  the  hoe,  the  plough, 
the  loom,  are  inseparable  means  and  companions  of  his 
advancement ;  and  even  moral  instruction  is  wasted  upon 
him,  while  he  remains  a  brute.  He  cannot  begin  to  prac- 
tise Athe  Christian  virtues  while  he  is  sunk  in  ignorance, 
for  physical  comforts  as  well  as  moral  culture  are  indis- 
pensable to  his  elevation.  The  most  important  of  physical 
instruments  are  derived,  immediately  or  remotely,  from  the 
mineral  kingdom,  for  the  vegetable  world,  equally  with  the 
animal,  rests  upon  this  basis;  whether  we  speak  of  the 
cedar,  the  oak,  the  lichens,  or  the  grasses,  all  equally 
derive  their  support  from  the  elements  afforded  by  the 
mineral  world,  which,  in  its  widest  sense,  includes  not 
only  the  solid  earth,  but  its  waters,  and  all  its  fluids — its 
atmosphere,  and  all  its  gases.  The  vegetable  kingdom 
borrows  from  the  mineral  world  oxygen,  carbon,  hydro- 
gen ;  and  even  nitrogen  and  all  that  are  indispensable 
to  vegetable  life  are  found  in  the  waters  and  the  atmo- 
sphere, while  other  elements  or  compounds,  adapted  to 
particular  purposes,  are  derived  from  various  mineral 
sources ;  the  soil,  for  example,  affords  silica,  to  give 
strength  to  the  epidermis  of  grasses,  bamboos,  equi- 
seta,  &c. ;  and  potassa  and  soda,  derived  from  decom- 
posed felspar  and  from  other  minerals,  pass  by  absorption 
into  the  juices  of  plants.  Even  animal  and  vegetable 


8 


manures  form  no  exception,  for  their  elements  have  a  similar 
origin,  and  consist  almost  entirely  of  the  substances  indis- 
pensable to  vegetable  growth.  While,  therefore,  we  explore 
this  orb  of  fire  and  water,  and  solid  rock,  we  shall  gain  the 
most  interesting  knowledge,  and  much  positive  advantage. 
Our  beautiful  planet  is  indeed  worthy  of  our  study ;  it 
was  once  our  cradle — it  will  soon  be  our  grave  :  between 
the  dawn  and  the  night  of  life,  it  is  the  scene  of  our  busy 
action,  and  from  it  we  shall  rise  to  another  state  of  being. 

6.  DISCOVERY  OF  USEFUL,  MINERALS. — Geology  discloses 
to  us  the  valuable  minerals,  such  as  are  useful  to  society, 
and  teaches  us  where  to  expect  them,  and  where  research 
would  be  vain. 

Coal* — Duly  informed  in  this  science,, we  should  never 
look  for  coal  in  granite,  nor  among  beds  of  sand  and  clay, 
and  in  the  wide  intervening  series,  a  large  part  of  the 
formations  are  excluded  from  the  association  with  this  most 
important  mineral.  Do  we  find  slates  and  shales,  and 
limestones,  charged  with  bitumen,  and  burning  on  the  fire, 
— this  affords  a  presumption  of  some  value,  but  it  is  not 
decisive,  as  bitumen  is  associated  with  many  minerals  that 
do  not  belong  to  coal  formations.  The  impressions  of 
plants  on  the  rocks,  especially  those  charged  with  bitumen, 
strengthen  our  presumption ;  and  should  we  find  fragments 
of  coal  scattered  in  the  soil,  or  mingled  with  gravel  and 
sand,  in  the  banks  and  water  courses,  and  should  we  observe 
dark  masses  of  earth,  (called  by  the  miners  coal  blossoms,) 
which,  on  close  inspection,  appear  to  contain  fine  coaly 
matter,  we  may  presume  that  beds  of  this  combustible  may 
be  near,  and  that  it  may  be  proper  to  dig  or  bore ;  and 
when,  at  last,  we  find  the  beds  of  coal,  they  will  be  regu- 
larly arranged  between  roof  and  floor  of  rock,  which  is 
commonly  coal  slate  or  shale.  But  it  by  no  means  follows 

*  The  coal  strata  sometimes  repose  upon  granite,  (not  in  it,)  as  in 
France,  and  near  Richmond,  Virginia. 


9 


that  beds  of  slate  necessarily  indicate  coal :  those  of  the 
primary  series  would  scarcely  contain  any  combustible, 
unless  it  were  plumbago,  or  possibly  a  little  anthracite. 
The  geological  laws  of  coal  are  very  strict,  and  a  thorough 
acquaintance  with  them  is  an  effectual  safeguard  against 
fruitless  enterprises,  productive  only  of  expense  and  dis- 
appointment. 

Lignite. — It  is  easy  to  mistake  beds  of  lignite  for  coal : 
lignite,  when  found  in  sufficient  abundance,  is  a  valuable 
combustible,  but  it  is  not  coal ;  in  burning  it  emits  a  sharp 
and  acrid  odour,  like  the  smoke  of  a  wood  fire,  and  is  in  fact 
wood  only  altered  by  inhumation.  It  is  mostly  abundant 
in  the  more  recent  geological  formations,  especially  in  ter- 
tiary beds  of  sand,  gravel,  and  clay,  in  which  true  coal  is 
never  found.  The  trees  that  are  buried  in  the  more  recent 
alluvial  or  diluvial  deposits  are  little  altered,  and  are,  for 
the  greater  part,  readily  recognised  as  belonging  to  existing 
species:  but  sometimes  they  are  flattened  by  pressure, 
altered  in  their  texture,*  and  even  partially  carbonized. 

Vegetable  origin  of  coal.  —  Coal  is  entirely  of  vege- 
table origin :  hundreds  of  species  of  plants  have  been 
distinguished  in  the  coal  formation,  but  not  one  of 
them  is  found  at  the  present  time  living  on  the  earth, 
although  many  of  the  families  do  exist ;  but  their  species 
are  generally  of  a  diminutive  size,  in  comparison  with 
those  of  the  coal  period ;  and  those  modern  ones  that  ap- 
proach the  ancient  in  magnitude,  are  found  chiefly  in 
tropical  climates. 

Limestone  and  marbles. —  Limestone,  including  chalk 
and  marble,  is  a  most  useful  substance.  The  ancient 
Grecian  temples  give  decisive  proof  of  the  durability  of 
marble ;  and  its  beauty,  even  after  the  lapse  of  two  or 
three  thousand  years,  and  after  innumerable  aggressions 
by  the  violence  of  war,  or  the  depredations  of  antiquaries, 
*  Professor  Carpenter,  in  the  Am.  Jour.  vol.  xxxv.  No.  2. 


10 

more  destructive  than  the  action  of  the  elements,  is  not 
entirely  destroyed.  Limestone  is  the  most  important  in- 
gredient in  mortar,  and  is  of  great  value  in  soils.  But  it 
is  not  necessary  to  enlarge  on  a  subject  so  generally  under- 
stood. It  is  sufficient  to  say,  that  in  the  selection  of  lime- 
stone for  architectural  constructions,  or  to  afford  mortar  or 
a  fertilizing  ingredient  for  soils,  geological  skill  will  often 
prove  of  great  value ;  and  in  cases  of  high  responsibility, 
such  as  those  of  grand  public  edifices,  intended  to  endure 
to  distant  ages,  the  united  services  of  the  geologist,  the 
quarry-man,  and  the  stone-mason,  may  well  be  put  in 
requisition,  for  practical  artists  often  acquire  the  skill  to 
judge  very  correctly  of  the  value  of  materials.  The  ex- 
perience of  all  antiquity  proves  this  to  be  true. 

Various  rocks. — The  same  view  may  be  taken  of  granite 
and  sienite,  and  the  slaty  rocks  of  that  family,  of  porphy- 
ries, traps,  and  soapstones,  of  sandstones  and  pudding- 
stones,  or  breccias.  All  these,  and  more,  are  employed 
either  in  constructing  the  external  walls,  or  in  forming  the 
interior  decorations  of  buildings,  as  well  as  in  forts,  docks, 
bridges,  quays,  aqueducts,  and  roads,  and  it  is  of  the 
utmost  importance  that  time  and  expense  should  not  be 
bestowed  upon  materials  that  are  faulty  or  worthless ;  for 
sandstones,  limestones,  and  even  some  kinds  of  granite 
crumble  down  on  exposure  to  the  weather,  and  thus  pro- 
duce deformity  and  dilapidation,  where  every  thing  should 
be  solid  and  enduring. 

Mode  of  detection. — In  general,  this  error  may  be 
avoided  by  a  careful  observation  of  the  effects  of  time  and 
the  weather  upon  such  masses  of  rocks  as  chance  to  be 
prominent  above  the  ground,  and  have  therefore  been  (it 
may  be  for  ages)  subjected  to  those  atmospherical  agencies, 
which  the  finished  edifice  must,  in  its  turn,  encounter. 

Instances  of  premature  decay. — Had  these  precautions 
been  observed,  we  need  not  at  this  moment  see  splendid 


11 


aqueducts  crumbling  into  ruins,  before  they  are  twenty 
years  old  ;  nor  bricks  splitting  by  the  slacking  of  the  lime, 
that  was  burnt  into  quick  lime,  when  the  clay  containing 
it  was  baked,  and  thus  ruining  the  walls  of  houses ;  nor  the 
marble  steps  of  a  magnificent  Grecian  temple  crumbling 
at  their  edges  and  angles,  because  they  are  constructed  of 
feebly  coherent  dolomitic  marble;  nor  the  walls  of  the 
grandest  parliament  house  in  the  world  painted  with  white 
lead,  to  conceal  the  spots  of  iron  rust  developed  by  the 
air  upon  a  soft  sandstone  :  such  a  building  should  have 
been  constructed  of  granite  or  white  marble  ;  and  happily 
most  of  our  cities  are  now  able  to  present  magnificent 
edifices  of  these  materials,  upon  which  the  storms  and 
floods  of  thirty  centuries  may  beat  in  vain. 

Gypsum. — Plaster  of  Paris,  (chemically,  sulphate  of 
lime,)  is  of  great  value  to  the  agriculturist,  to  the  modeller, 
and  to  the  architect.  One  would  think,  that  as  it  is  used 
by  multitudes,  it  must  be  sufficiently  known,  and  that  a 
little  scientific  knowledge  would  prevent  the  quarry-men 
from  throwing  away  as  worthless,  the  pure  crystallized 
selenite,*  and  saving  only  the  darker  and  coarser  plaster. 
Still,  because  this  mineral  is  soft,  every  geologist  is  called 
on  to  give  his  opinion  upon  various  tender  stones,  supposed 
to  be  plaster  of  Paris.  The  varieties  of  chlorite  and 
of  chloritic  slates,  and  of  talc,  soapstone,  and  steatitic 
minerals,  are  most  usually  mistaken  for  plaster,  and  even 
the  limestones  are  sometimes  confounded  with  it.  In 
the  former  instances,  the  labour  of  grinding  is  lost  to 
the  farmer,  as  those  minerals  are  not  known  to  produce 
any  beneficial  effect  upon  soils,  but  the  case  is  not  the 
same  with  the  latter,  which  may  prove  highly  advan- 
tageous, f  A  very  moderate  acquaintance  with  the  charac- 
ters of  minerals  would  prevent  these  mistakes,  so 

•  As  was  done  in  the  State  of  New  York. 

t  As  happened  a  few  years  since,  at  Genesco,  State  of  New  York. 


12 


discouraging  and  injurious  to  rural  industry  ;  and  persons 
unacquainted  with  mineralogj',  should  not  incur  the 
hazard  of  time  or  property  without  first  consulting  those 
who  are  qualified  to  judge. 

Marls. — Marls  also  are  of  great  importance  to  agricul- 
ture, and  many  barren  tracts  have  been  redeemed  and 
brought  to  fertility  by  a  judicious  use  of  these  substances. 
But  as  the  earthy  materials  which  bear  the  name  of  marl, 
are  often  extremely  similar  in  their  aspect  to  clays,  it  is 
important  to  distinguish  them  correctly,  and  this  is  done 
by  inspection,  where  there  are  visible  fragments  of  shells, 
and  other  animal  remains.  Usually,  the  calcareous  matters 
are  so  minutely  divided  and  blended  with  the  earthy 
materials,  that  they  cannot  be  detected  by  the  eye,  and  we 
must  resort  to  chemical  trials  by  acids  or  by  fire.  These 
trials  are  easy  rand  decisive,  and  may  save  the  practical 
farmer  from  the  double  disappointment  and  vexation  of 
covering  his  land  with  that  which  is  not  only  unprofitable, 
but  which  may  also  be  injurious  to  vegetable  growth. 
It  may  happen  that  a  substance  which  is  not  marl  may 
prove  useful,  as  when  sand  is  mingled  with  clay,  or  clay 
with  sand;  the  former,  to  correct  a  soil  too  stiff  and 
tenacious,  the  latter,  one  that  is  too  open  and  too  little 
retentive.  It  is,  however,  rare,  that  on  a  large  scale 
such  mixtures  can  be  made  by  art,  without  ruinous  ex- 
pense ;  it  may  answer  to  prepare  a  soil  for  a  garden,  or 
other  grounds  of  limited  extent,  but  in  general,  we  can 
only  correct  deficiencies;  we  cannot  afford  to  make  a 
soil  anew. 

Metals. — The  researches  for  metals  have  ever  interested 
mankind  in  a  high  degree,  and  on  no  subject  are  they 
more  liable  to  error  and  imposition. 

Iron. — Happily,  the  most  important  metal  is  the  most 
abundant.  But  iron  ores  are  not  always  known  by  the  un- 
instructed;  some  of  the  most  valuable  are  not  attracted  by 


13 


the  magnet,  until  they  have  been  heated  in  contact  with 
carbon  or  hydrogen ;  while  others  are  so  completely  dis- 
guised, that  they  are  not  recognised  at  all  by  those  ac- 
quainted with  the  purified  metal  alone.  This  arises  from 
their  combination  with  various  substances,  chiefly  oxygen, 
sulphur,  acids,  or  arsenic,  which,  on  account  of  the  great 
change  they  produce  in  the  properties  of  metals,  are  called 
mineralizers.  Iron  pyrites,  an  abundant  mineral  of  little 
value,  is  frequently  mistaken  for  gold,  because  it  is  usually 
yellow,  and  this,  notwithstanding  that  it  is  hard  and  brittle, 
while  gold  is  soft  and  malleable.  Yellow  mica  is  gathered 
for  gold  dust,  and  silvery  mica  and  white  arsenical  iron  are 
taken  for  silver. 

Calamine,  the  native  oxide  of  zinc,  and  tin-stone,  the 
native  oxide  of  tin,  have  no  resemblance — the  former,  to 
any  metal  whatever,  and  the  latter  has  none  to  tin,  while 
both  might  be  rejected  by  an  ignorant  observer.  The  same 
may  be  said  of  the  sulphuret  of  silver,  the  grey  sulphuret 
of  copper — the  chromate — molybdate — carbonate — phos- 
phate— and  sulphate  of  lead,  and  many  more.  Few 
persons  do,  indeed,  trust  themselves  to  carry  on  great 
works  in  mining,  without  previously  consulting  professional 
men  ;  some  are,  however,  so  perverse,  or  blinded,  as  to 
persist  even  against  the  best  counsels,  and  they,  of  course, 
pay  the  forfeit  of  their  folly  in  disappointment,  and  some- 
times in  ruin. 

Divining  rod. — Many  more,  however,  yield  themselves 
both  blind  and  willing  dupes  to  the  miserable  delusions  or 
villany  of  the  divining  rod.  Too  often  does  it  happen, 
even  now,  that  the  professional  man  is  consulted,  not  to 
know  whether  the  divining  rod  has  any  virtues,  but  to 
ascertain  how  they  may  be  best  applied,  to  enrich  the 
credulous  inquirer;  and  the  geologist  who  can  reply  to 
such  persons  with  temper  and  kindness,  does,  indeed,  no 
more  than  his  duty,  although  he  might  be  pardoned  for  a 


14 


sharp  rebuke — deserved  certainly  by  the  diviner,  if  not 
by  his  convert. 

Geological  associations  of  metals. — It  is  well  known  to 
geologists,  that  metallic  veins  are  rarely  found  in  the  most 
recent  formations  and,  with  the  exception  of  iron,  and  of 
alluvial  deposits  of  other  metals,  they  rarely  occur  in 
great  abundance,  until  in  the  descending  series  we  ap- 
proach or  pass  the  geological  epoch  of  coal.  In  the 
transition  rocks,  certain  metals  abound,  while  others  fre- 
quent the  primary,  and  there  is  no  rock  so  old  that  it  may 
not  contain  some  of  the  metals. — Sound  scientific  views  of 
the  geological  structure  of  a  country  will  therefore  serve 
as  an  important  guide  in  the  research  for  metals,  or  in 
lorming  a  conclusion  as  to  the  probable  continuance,  en- 
largement, or  cessation  of  metallic  veins. 

Decisions  of  science. — The  negative  which  science  often 
pronounces  with  entire  confidence,  may  save  many  a  san- 
guine mind  from  delusion,  and  preserve  for  agriculture,  and 
the  useful  arts  of  life,  the  resources  which  might  have  been 
lavished,  in  reckless  profusion,  upon  vain  and  unproductive 
mining  operations.  It  is  rare  that  metallic  mines  will 
justify  the  abandonment  of  a  useful  calling,  in  the  common 
walks  of  life  ;  even  where  there  is  abundance  of  valuable 
ore,  few  individuals  can,  alone,  afford  to  encounter  the 
enormous  expense  of  mining,  and  to  wait  its  uncertain, 
and  it  may  be,  distant  and  stinted  returns.  A  good  quarry 
of  soapstone,  granite,  gypsum,  or  sandstone,  may  be  worth 
more  than  a  mine  of  gold,  and  such  have  actually  been 
the  results  in  some  signal  cases  in  this  country.  To 
these  few  instances  of  the  importance  of  geological  know- 
ledge to  the  common  interests  of  life,  many  more  might 
be  added,  but  these  are  sufficient  to  illustrate  our  argument, 
if,  indeed,  it  be  necessary  to  prove  that  he  who  acts  with 
consummate  knowledge  proceeds  with  safety — walking  in 
the  full  and  certain  light  of  science  j  while  he  who  adven- 


15 


tures  in  the  dark,  has  no  right  to  expect  anything  but 
disaster  and  ruin. 

Geological  surveys  by  public  authority. — That  there  is 
some  just  appreciation  of  this  subject  among  the  people  of 
this  country,  is  sufficiently  evinced  by  the  geological 
surveys  of  many  states  and  territories,  either  already  ac- 
complished, or  in  progress.  About  one  half  of  the  states 
have,  by  public  authority,  instituted  such  surveys  ;  the 
reports  which  have  been  published,  evince  industry,  know- 
ledge, and  skill ;  great  progress  has  been  made  in  develop- 
ing the  mineral  resources  of  the  country,  and  in  amassing 
stores  of  materials  to  serve  for  a  future  digested  and  syste- 
matical account,  both  scientific  and  practical,  of  North 
American  geology;  while,  at  the  same  time,  excellent 
schools  are  thus  established,  in  which  to  form  young 
geologists  by  actual  and  responsible  explorations  among 
mines  and  mountains.  These  good  works  will,  we  trust, 
proceed,  until  our  whole  territory  has  been  surveyed, 
when  some  gifted  individual  will  give  us  the  grand  result. 
In  a  scientific  relation,  these  researches  are  deeply  inter- 
esting, and  we  are  in  this  way,  as  well  as  by  personal 
efforts,  contributing  our  share  of  materials  towards  the 
general  stock  of  geological  knowledge. 

7.    SOME    FEATURES     IN    NoRTH    AMERICAN    GEOLOGY. 

Perhaps  no  country  is  more  favoured  in  the  nature,  abun- 
dance, variety,  and  distribution  of  the  most  important 
mineral  treasures.  The  limits  of  these  preliminary  re- 
marks must  prevent  even  the  most  general  summary  of 
our  geological  formations,  or,  at  most,  admit  of  nothing 
more  than  a  skeleton  ;  but  the  materials  for  information 
are  already  abundant,  and  are  yearly  increasing,  as  may 
be  seen  in  the  various  public  reports,  in  the  transactions 
of  learned  societies,  and  in  the  journals  of  science. 

Of  the  primary  and  transition  rocks,  to  which  we  may 
add  the  coal  formation  and  the  early  secondary,  we  have 


16 


immense  ranges,  extending  in  a  north-easterly  and  south- 
westerly direction,  through  the  continent,  and  comprising 
most  of  the  minerals  and  many  of  the  fossils  that  are 
found  associated  with  such  groups  in  the  old  world. 

The  Alleghanies,  (including  many  mountains  having  local 
names,)  following  the  general  bearing  of  N.  E.  and  S.W., 
and  ranging  between  the  Mississippi  and  the  Atlantic, 
form,  with  their  branches  and  connected  chains,  the  great 
rain-shed  of  the  countries  east  and  west ;  and  rising  to  two, 
three,  four,  and  five  thousand  feet  and  more,*  give  direc- 
tion to  the  streams  and  rivers,  either  to  the  Mississippi, 
the  Atlantic,  or  the  great  lakes  and  the  St.  Lawrence. 

Rocky  Mountains. — In  like  manner,  the  far  more  stu- 
pendous chains  of  the  Rocky  Mountains,  whose  loftiest 
peaks  are  reported  to  be  between  three  and  five  miles 
high,f  give  a  geological  character  to  the  regions  east  and 
west,  in  which  directions  the  waters  flow  to  the  Mississippi 
and  to  the  Pacific,  while  other  contributions  descend  to  the 
Gulf  of  Mexico  and  to  the  Northern  Ocean.  It  is  to  be 
regretted,  that  in  the  United  States  proper,  there  are  no 
mountain  ridges  or  solitary  peaks  that  pierce  the  region 
of  perpetual  snow. 

Mount  Washington. — Mount  Washington,  of  the  White 
Mountain  group  in  New  Hampshire,  which  approaches  a 
mile  and  a  quarter  in  height,  although  in  44°  of  north  lati- 
tude, and  on  a  continent  whose  average  temperature  is 
many  degrees  below  that  of  Europe,  throws  off  its  snowy 
mantle  only  for  a  short  season,  in  the  months  of  July  and 
August,  while  it  is  clad  in  white  during  the  remaining 
months  of  the  year.  Even  on  the  first  day  of  September, 
(1837,)  as  adventurers  upon  this  Alpine  mountain,  \  we 

*  Professor  Mitchell,  University  of  Chapel  Hill,  states  that  the  top  of 
Black  Mountain,  in  North  Carolina,  is  G47G  feet  above  the  level  of  the 
ocean.  See  Am.  Journal,  vol.  xxxv.  No.  2. 

t  See  Professor  Renwick's  Outlines  of  Geology.' 

J  'See  Am.  Jour.  Science,  vol.  xxxiv.  p.  74. 


were,  both  on  its  flanks  and  summit,  involved  in  a  wintry 
tempest  of  congealed  vapour,  formed  into  splendid  groups 
of  feathery  and  branching  crystals,  unlike  to  the  snows  of 
the  lower  regions ;  the  driving  masses  came  in  fitful  gusts, 
veiling  in  a  white  cloud  all  objects,  far  and  near;  but 
breaking  occasionally  to  admit  a  flood  of  solar  light  to 
render  visible  this  hoary  pinnacle,  and  the  deep  gorges  and 
valleys  of  the  neighbouring  groups  of  mountains.  The 
mountains  of  Essex  county,  State  of  New  York,  between 
Lake  Champlain  and  the  St.  Lawrence,  approach  the 
White  Mountains  in  altitude,  but  no  one  of  them  is  per- 
manently snow-clad. 

Mountains  of  central  Europe. — It  is  otherwise  in  Europe, 
whose  grand  central  group,  of  Mount  Blanc,  and  the 
various  Alpine  mountains,  rise  far  into  the  region  of  per- 
petual congelation ;  and  Mount  Blanc  would  pierce  that 
region  even  at  the  equator.  Thus  is  provided  an  eternal 
storehouse  of  ice  and  snow,  over  whose  wintry  surface  the 
winds,  rendered  heavier  by  contact,  glide  into  the  valleys 
and  plains  of  the  countries  at  their  feet,  and  thus  temper 
even  the  warm  climate  of  Italy,  preventing  the  extreme 
vicissitudes  which  we  experience. 

But  these  immense  natural  magazines  have  a  still  more 
important  relation  to  the  irrigation  of  the  vicinal  countries. 
The  melting  by  the  heat  of  summer,  supplies  copious 
streams  to  feed  the  innumerable  rivers  that  flow  from  these 
grand  fountains,  to  almost  every  part  of  continental  Europe, 
south  of  the  Baltic.  Thus,  the  effects  of  drought  are,  in  a 
great  measure,  prevented,  while  destructive  mountain- 
floods  are  of  rare  occurrence.  From  the  absence  of  such 
mountains,  we  have  no  permanent  stores  of  ice  and  snow, 
and,  consequently,  our  rivers  are  liable  to  extreme  varia- 
tions of  altitude  and  force.  The  Ohio,  in  midsummer, 
sometimes  leaves  numerous  fleets  aground,  while  occa- 
sional risings,  from  deluging  rains,  aided  perhaps  by  the 


18 

melting  of  the  snows  of  vast  regions,  swell  the  river  to  an 
immense  flood,  that  spurns  the  barrier  of  the  banks,  lays 
villages  and  cities  under  water,  and,  expanding  into  an 
internal  sea,  rushes  with  wasting  violence  over  the  wide- 
spread meadows  and  farms.  For  this  reason,  hydraulic 
engineering  is,  in  this  country,  attended  with  peculiar  diffi- 
culties, both  on  account  of  a  deficiency  and  an  excess  of 
water;  the  former  rendering  the  works  inoperative,  and 
the  latter  invading  or  sweeping  them  away.  The  future 
civilized  inhabitants  of  the  countries  near  the  Rocky  Moun- 
tains, (excepting,  of  course,  the  immense  sandy  deserts, 
which,  near  the  eastern  slope,  emulate  the  sterility  of 
Arabia  and  Zahara,)  will  enjoy  advantages  in  many  re- 
spects similar  to  those  of  Piedmont,  Switzerland,  Germany, 
and  France ;  and  it  is  easy  to  predict,  that  peculiar  struc- 
tures, and  a  peculiar  state  of  society,  will  be  modelled  upon 
the  sublime  physical  features  of  those  truly  Alpine  regions. 
From  this,  his  native  land,  we  have  too  much  reason  to 
expect,  that,  despite  of  the  efforts  of  the  benevolent  to 
avert  the  impending  doom}  the  red  man  of  the  forest,  not 
reclaimed  to  humanity,  but  abandoned  to  his  fate,  will 
vanish  before  the  prevailing  arts  and  power,  and  the  still 
more  prevailing  seductions,  of  civilized  life — the  extermi- 
nated victim  of  cupidity  and  cruelty. 

Influence  of  geological  structure  on  society. — It  is  per- 
fectly apparent  to  geologists,  that  the  scenery  of  a  country 
is  not  more  exactly  stamped  by  its  geological  formations, 
than  are  the  manners  and  employments  of  its  inhabitants. 
This  argument,  so  beautifully  displayed  by  Dr.  Buckland,* 
with  respect  to  England,  is  capable  of  an  equally  satisfac- 
tory application  to  this  country. 

New  England. — The  bleak  hills  and  long  winters  of  New 
England  are  unfavourable  to  the  most  extensive  and  profit- 
able agricultural  pursuits,  while  the  extensive  and  deeply 
*  Bridge\vater  Treatise. 


10 


indented  sea-coasts,  abounding  with  harbours,  headlands, 
rivers,  and  inlets,  naturally  produce  an  impulse  towards 
the  ocean,  which,  conspiring  with  the  original  adventurous 
character  of  the  population,  sends  them  roving  from  the 
arctic  to  the  antarctic  circle,  till  the  wide  world  is  laid 
under  contribution  by  their  enterprise.  Their  numerous 
streams  and  waterfalls  furnish  the  cheapest  means  for 
moving  machinery,  and  thus  manufactories  spring  up 
wherever,  in  their  expressive  phraseology,  there  is  water- 
power  ;  and  steam  supplies  local  deficiencies  of  moving 
force.  Ingenuity,  conspiring  with  a  general  system  of 
education,  is  excited,  under  such  culture,  to  produce  nume- 
rous inventions,  and  hosts  of  young  men  seek  their  for- 
tunes successively  abroad,  as  mechanics — seamen — traders 
— instructors  and  politicians,  who  thus  operate  powerfully 
and,  we  trust,  beneficially  on  other  communities. 

Southern  states. — The  immense  tracts  of  rich  alluvium 
in  the  southern  states — the  mildness  of  the  climate — the 
coasts,  less  abounding  with  safe  inlets,  and  often  modified 
by  the  action  of  the  existing  ocean,  with  a  population  not 
originally  commercial,  give  a  decided  impulse  to  agri- 
culture, and  a  few  great  staples  form  the  chief  reliance 
of  the  landholders.  It  is  easy  to  see  that  this  state  of 
things  grows  out  of  the  recent  secondary,  the  tertiary,  and 
the  alluvial  formations,  which  constitute  the  ocean-barrier, 
from  Staten  Island  to  Florida,  and  from  Florida  to  Texas, 
extending  inland  toward  the  mountains. 

Western  states.  —  In  the  west,  the  boundless  fertile 
prairies,  and  other  tracts  of  productive  soil,  conspire  with 
remoteness  from  the  ocean  to  indicate  agriculture  and 
pasturage  as  the  main  employment  of  the  inhabitants,  while 
exhaustless  beds  of  coal,  limestone,  plaster  of  Paris,  and 
iron,  and  rich  deposits  of  lead  and  copper,  and  salt  foun- 
tains, both  numerous  and  copious,  furnish  means  for  a 
manufacturing,  as  well  as  an  agricultural  population. 
c2 


20 

These  pursuits  occupy  the  greater  number  of  the  people, 
while  many  find  a  profitable  employment  in  navigating 
those  immense  inland  seas — the  great  lakes  and  the  vast 
rivers,  which  run  thousands  of  miles  before  they  mingle 
with  the  ocean. 

What  geologist  fails  to  perceive  that  this  state  of  things 
is  the  result  of  the  immense  lower  secondary  and  transition 
formations  which  cover  the  western  states,  sustaining  por- 
tions of  tertiary,  and  like  all  countries,  alluvial  depositions  ? 
While  New  England  produces  granite,  marble,  and  other 
building  materials,  of  excellent  quality,  Pennsylvania,  with 
the  western,  and  several  of  the  southern  and  south-western 
states,  supplies  inexhaustible  magazines  of  coal,  to  prompt 
and  sustain  the  manufacturing  interests  of  this  wide  coun- 
try, and  to  aid  its  astonishing  navigation  by  steam,  already 
of  unexampled  extent,  on  its  internal  waters,  and  destined, 
at  no  distant  day,  to  compete  on  the  main  ocean  in  ami- 
cable rivalry  with  our  parent  country. 

Geological  treasures. — Our  coal  formations,  in  richness 
and  extent,  are  unrivalled  in  the  whole  world ;  our  iron  and 
lead  are  in  the  greatest  abundance  and  excellence  ;  Missouri 
has  mountains  of  pure  oxide  of  iron,  that  have  no  compeers ; 
and  there  is  a  fair  prospect  that  copper  will  also  abound  in 
the  west.  We  have  great  deposits  of  limestone  and  marble, 
of  plaster  of  Paris,  marl,  and  salt,  and  of  building  stones,  of 
almost  every  kind ;  our  soils  are  so  various  in  quality,  and 
in  geographical  position,  that  almost  every  agricultural  pro- 
duction is  obtained  in  abundance.  It  is  obvious,  then, 
that  we  have  all  the  physical  elements  of  national  and 
individual  prosperity,  and  that  the  blame  will  be  our  own, 
if  we  do  not  follow  them  up  by  proper  moral  and  intellec- 
tual culture,  which,  alone,  can  render  them  sources  of 
public  and  private  happiness. 

Geological  deficiencies — upper  secondary. — Of  the  upper 
secondary,  below  the  chalk,  and  above  the  new  red  sand- 


'21 


stone,  lying  higher  than  the  coal,  we  have  no  well  ascer- 
tained strata :  rocks  of  oolitic  Structure  we  may  have,  but 
it  is  not  ascertained  that  we  have  the  true  oolite  of 
England  and  continental  Europe,  nor  have  we  traced  the 
wealden  nor  the  lias,*  with  their  colossal  animal  wonders. 

Equivalent  of  chalk. — Chalk,  properly  speaking,  appears 
to  be  absent  from  the  United  States,  but  there  is  an  equi- 
valent to  the  chalk  formation,  containing  similar  fossils, 
between  the  Delaware  River  and  the  shores  of  New  Jersey, 
as  well  as  in  various  places  in  the  south,  and,  as  we  are 
recently  assured,  in  Missouri.f 

Absence  of  volcanoes. — The  principal  deficiencies  in  the 
geological  formations  of  the  United  States,  are  in  the 
absence  of  active  volcanoes,  and  of  most  of  the  members 
of  the  upper  secondary.  However  delightful  active  vol- 
canoes, with  their  earthquakes  and  eruptions,  may  be  to 
speculative  geologists,  the  sober,  unscientific  population, 
may  well  rest  quite  contented  without  them,  satisfied  to 
barter  the  sublime  and  terrific,  for  quiet  and  safety.  Al- 
though the  soils  formed  from  decomposed  lava  are  often 
amazingly  fertile,  and  the  vine  flourishes  on  the  flanks,  and 
at  the  feet  of  volcanic  mountains  of  warm  countries,  these 
influences  are  too  local  to  be  of  much  importance  to  agri- 
culture. 

Within  the  United  States  proper,  including  the  states 
and  territories  beyond  the  Mississippi,  and  east  of  the 
Alleghany  mountains,  there  is  not,  so  far  as  we  know,  a 
single  active  volcano,  nor  even  an  unequivocal  crater  of 
one  that  is  dormant.  It  remains  yet  to  be  decided, 
whether  in  and  beyond  the  Rocky  Mountains,  quite  to  the 
shores  of  the  Pacific  Ocean,  there  are  any  active  volcanoes 
within  our  parallels  of  latitude. 

*  It  is  plain  that  the  lias,  so  called  ia  the  west,  is  not  the  lias  of 
England. 

t  See  Dr.  Morton's  Synopsis  of  Organic  Remains  of  the  Green  Sands  of 
the  United  States,  1  vol.  8vo.  with  plates. 


22 


Both  north  and  south  of  our  limits,  there  are,  on  the 
Pacific  shores  and  the  islands,  numerous  volcanoes,  and  it 
would  be  strange  indeed  if  there  were  none  within  our 
extensive  possessions  on  the  same  coasts. 

Records  of  igneous  action  in  the  far  West. —  However  this 
may  be,  there  remains  no  doubt  that  the  volcano  has  done 
its  work,  on  a  great  scale,  among  the  Rocky  Mountains,  and 
between  them  and  the  Pacific  ;  for  all  our  travellers  attest 
the  existence  of  immense  regions  covered  with  scoriae  and 
other  decidedly  igneous  products,  as  if  there  had  been 
actual  and  vast  eruptions  within  a  period  too  short  for 
decomposition  to  have  reduced  these  tumefied  and  semi- 
vitrified  masses  to  soil. 

Trap  and  basalt. — Regular  formations  of  trap  and  of 
basalt,  with  symmetrical  columns,  are  common  among  and 
beyond  the  Rocky  Mountains,  and  the  rocks  of  this  igneous 
family  are  frequent  in  many  parts  of  the  old  United  States. 
They  abound  in  New  England,  New  Jersey,  and  the 
Carolinas,  and,  as  usual  elsewhere,  they  protrude  their 
dykes  among  other  rocks.  We  are  not  aware  that  they 
have  invaded  tne  coal,  as  in  Europe  ;  but  in  New  England, 
and  especially  in  New  Hampshire,  they  often  divide  the 
primary  rocks,  cutting  even  granite  mountains  from  top  to 
bottom ;  branching  ,.  rft,  in  many  places,  with  numerous 
veins,  either  dying  away  to  extinction,  or,  perchance,  re- 
turning again  to  the  main  current  after  having  cut  off  a 
portion  of  the  invaded  rock.  The  White  Mountains  of 
New  Hampshire  abound  with  such  features. 

Phenomena  of  a  like  nature  are  found  in  the  mountains 
of  Essex,  Lake  Champlain,  New  York,  and  in  many  other 
places ;  and  the  primary  rocks  on  the  coasts  of  Massachu- 
setts and  Maine,  as  well  as  in  the  interior,  are  wonderfully 
cut  up,  by  invading  veins  and  dykes  of  trap,  basalt,  and 
porphyry,  and  even  of  granite  itself.  It  appears,  also, 
that  in  the  state  of  New  York  there  are  similar  intrusions 


23 

into  other  rocks,  including  the  primary,  and  not  excepting 
granite.* 

Tertiary  formations. — Our  tertiary  formations  are  ex- 
ceedingly extensive,  and  are  rich  in  fossils,  chiefly  of  the 
earlier  eras.  They  bound  a  large  portion  of  the  sea  coasts 
south  of  New  England,  quite  to  the  Mexican  Gulf,  and  up 
the  Mississippi  and  Missouri:  these  oceanic  deposits  are 
found,  also,  extending  hundreds  of  miles  into  the  interior 
from  the  coasts,  where,  as  well  as  near  the  sea,  they  furnish, 
in  the  calcareous  marls,  inexhaustible  resources  for  agri- 
culture. Even  on  the  shores  of  New  England,  there  are 
marine  tertiary  deposits,  as  at  Gay  Head,  in  Martha's 
Vineyard,  and  elsewhere  in  that  vicinity,  while  there  are, 
in  every  part  of  the  United  States,  innumerable  inland 
deposits  of  fresh  water  tertiary. 

Boulders. — In  boulders  and  rocks  of  transport  our 
country  abounds  ;  vast  regions  of  older  secondary,  and  of 
transition,  are  occupied,  more  or  less,  by  ruins  of  primary 
rocks,  some  of  them  of  vast  size,  while  the  primary 
countries  themselves,  and  the  transition  too,  are  marked 
by  their  own  disjecta  membra.  We  are  precluded  by  our 
limits  from  discussing  the  causes  of  their  transportation, 
whether  by  floods,  ice  floes,  or  other  motive  powers. 

It  is  almost  unnecessary  to  remark,  that  pebbles,  gravel, 
and  sand,  are  found,  as  in  other  countries,  transported  and 
arranged,  without  doubt,  by  the  action  of  water. 

8.  BEAUTY  AND  INTEREST  OF  GEOLOGY  AS  A  SCIENCE. — 
In  relation  to  the  beauty  and  interest  of  geology  as  a 
science,  we  can  hardly  trust  ourselves  to  write,  since, 
within  our  prescribed  limits,  we  have  no  room,  as  there  is 
little  occasion  to  describe  adequately  that  which  our  author 
has,  everywhere,  treated  with  signal  ability  and  interest. 
It  may,  however,  serve  to  engage  the  attention  of  those  to 
whom  geology  is  a  terra  incognita,  if  we,  in  this  place, 

*  See  Professor  Hall,  in  the  Geological  Reports  for  1838. 


24 


remark,  that  no  field  of  science  presents  more  gratifying, 
astonishing,  and  (but  for  the  evidence)  incredible  results. 
Man  has  been  but  a  few  thousand  years  a  tenant  of  this 
world;  nothing  which  we  discover  in  the  structure  of  the 
earth,  would  lead  us  to  infer  that  he  existed  at  a  period 
more  remote  than  that  assigned  to  him  by  the  Scriptures. 
Had  he  been  cotemporary  with  the  animals  and  plants  of 
early  geological  periods,  we  should  have  found  his  remains 
and  his  works  entombed  along  with  them. 

Opinion  of  Berkeley. — This  argument  forcibly  impressed 
the  mind  of  Bishop  Berkeley,  a  century  ago,  and  the  follow- 
ing beautiful  passage  from  his  works  is  cited  by  Mr.  Lyell.* 
"  To  any  one  who  considers  that  on  digging  into  the  earth, 
such  quantities  of  shells,  and  in  some  places,  bones  and 
horns  of  animals,  are  found  sound  and  entire,  after  having 
lain  there,  in  all  probability,  some  thousands  of  years ;  it 
would  seem  probable  that  gems,  medals,  and  implements 
in  metal  or  stone,  might  have  lasted  entire,  buried  under 
ground  forty  or  fifty  thousand  years,  if  the  world  had  been 
so  old.  How  comes  it  then  to  pass  that  no  remains  are 
found,  no  antiquities,  of  those  numerous  ages  preceding  the 
scripture  accounts  of  time ;  that  no  fragments  of  buildings, 
no  public  monuments,  no  intaglios,  cameos,  statues,  basso- 
relievos,  medals,  inscriptions,  utensils,  or  artificial  works  of 
any  kind,  are  ever  discovered,  wrhich  may  bear  testimony 
to  the  existence  of  those  mighty  empires,  those  successions 
of  monarchs,  heroes,  and  demi-gods,  for  so  many  thousand 
years?  Let  us  look  forward,  and  suppose  ten  or  twenty 
thousand  years  to  come,  during  which  time  we  will  sup- 
pose that  plagues,  famine,  wars,  and  earthquakes,  shall 
have  made  great  havoc  in  the  world,  is  it  not  highly 
probable,  that  at  the  end  of  such  a  period,  pillars,  vases, 
and  statues,  now  in  being,  of  granite,  or  porphyry,  or 
jasper,  (stones  of  such  hardness  as  we  know  them  to  have 
*  Principles,  5th  Ed.,  vol.  iii.  p.  255. 


25 


lasted  two  thousand  years  above  ground,  without  any  con- 
siderable alteration,)  would  bear  record  of  these  and  past 
ages  ?  or  that  some  of  our  current  coins  might  then  be 
dug  up,  or  old  walls,  and  the  foundations  of  buildings, 
show  themselves,  as  well  as  the  shells  and  stones  of  the 
primeval  world,  which  are  preserved  down  to  our  times."* 
This  remarkable  passage  proves  that  the  great  man  from 
whom  it^  fell,  saw  the  geological  argument  in  a  true  light, 
and  felt  its  force  to  such  a  degree  as  to  convince  him  of  the 
great  antiquity  of  the  earth,  which  he  justly  viewed  as  in 
no  way  inconsistent  with  the  comparatively  recent  origin 
of  man,  or  with  the  historical  account  of  both  events  con- 
tained in  the  Genesis.  It  is  easy  to  understand  how  such 
a  mind  would  have  been  convinced,  warmed,  and  excited 
even  to  enthusiasm,  by  the  discoveries  that  have  burst 
upon  us  during  the  last  fifty  years. 

9.  ORGANIC  REMAINS. — We  descend  from  the  alluvial 
under  our  feet,  through  the  strata,  the  lowest  of  which  lies 
upon  the  granite,  or  the  early  slates,  and  we  are  seldom  with- 
out the  records  of  life,  in  ages  long  past,  and  those  records 
are  drawn  both  from  the  animal  and  vegetable  kingdom. 

Ancient  animals. — Shells  and  molluscous  and  testaceous 
animals  are  everywhere  seen ;  their  forms,  their  casts,  their 
substance,  are  apparently  preserved  in  stone,  but  really 
converted,  by  the  substitution  of  mineral  matter,  into  true 
fossils.  Myriads  on  myriads  of  these  things  are  found,  not 
merely  in  the  visible,  superficial  strata,  but  in  the  heart  of 
the  mountains,  and  at  profound  depths,  forming  an  essen- 
tial part  of  the  solid  framework  of  the  globe.  The  animals 
and  plants  are  not  accidental  resemblances,  but  authentic 
specimens  of  organic  antiquity,  inclosed  in  the  strata  and 
mountains,  as  the  materials,  in  mechanical  or  chemical 
suspension  in  the  waters,  concreted  around  them.  It  was 
impossible  that  they  should  be  due  to  any  sudden  or  acci- 

*  Alciphron,  or  the  Minute  Philosopher,  vol.  ii.  pp.  84,  85.    1732. 


dental  event ;  the  organic  beings  came  into  life  as  now — 
performed  their  parts  as  now,  and  were  entombed  in  the 
forming  masses,  which  were,  therefore,  of  more  recent  origin. 

Fossil  fishes. — If  we  descend  ;with  Agassiz  *  from  the 
strata  of  newest  formation,  to  those  that  lie  near,  or  upon 
the  primary  rocks,  we  are  astonished  and  delighted  to  find 
not  only  that  crustaceous  and  molluscous  animals,  of  various 
kinds,  have  existed  in  the  early  ages,  but  that  fishes  have 
also  occupied  the  waters  of  almost  all  geological  ages,  since 
life  began ;  and  that  among  the  earliest,  even  those  that  are 
buried  beneath  the  coal,  there  were  races  of  great  size, 
power,  and  ferocity;  formidable  from  their  teeth  and  jaws, 
which  had,  in  some  species,  the  structure  of  carnivorous 
reptiles,  and  whose  forked  tails,  with  unequal  flukes,  en- 
abled them  quickly  to  turn  over  on  their  backs  before 
striking  their  prey.  The  fossil  fishes,  of  particular  genera 
and  species,  are  characteristic  of  particular  geological  form- 
ations ;  they  extend  geographically,  far  and  wide,  to  distant 
countries,  so  that  certain  species  may,  if  found  at  all,  be 
expected  in  similar  rocks  in  Europe,  in  America,  in  Asia, 
and  Africa,  and  they  are  of  every  size,  from  inches,  and 
fractions  of  an  inch,  to  several  feet.  They  occur  either 
solitary — or  in  groups — or  in  fragments — or  in  immense 
shoals,  like  those  of  Mount  Bolca,  near  Verona,  in  Italy, 
where  there  are  more  than  one  hundred  species ;  still  not 
a  single  fish  of  the  strata  that  [precede  the  most  recent  ter- 
tiary, is  identical  in  species  with  any  now  existing  in  the 
waters  of  the  globe. 

Fossil  vegetables.  — Vegetables  are  found  in  nearly  all 
geological  ages,  and  the  labours  of  Count  Sternberg,  of  M. 
Adolphe  Brongniart,  and  others,  have  proved  that  a  pecu- 
liar vegetation,  adapted  to  the  temperature,  the  degree  of 
moisture,  and  other  circumstances  of  the  earth's  successive 
surfaces,  attended  the  different  geological  epochs. 

*  The  great  writer  oil  fossil  ichthyology,  of  Neufchatel. 


27 

Splendid  and  expensive  works  are  now  in  the  hands  of 
geologists,  containing  exact  delineations  of  the  fossil  vege- 
tables, so  far  as  they  have  been  ascertained.  They  are  of 
all  dimensions,  from  minute  confervae  and  lichens,  to 
gigantic  trees;  their  structure,  from  mere  fragments  and 
ruins,  to  perfect  plants  and  trees,  has  been  beautifully 
displayed — roots,  trunks,  branches  and  leaves,  with  the 
most  delicate  ramifications  of  the  skeletons  of  the  latter; 
in  some  rare  cases,  the  more  perishable  organic  fructifica- 
tion has  been  made  out,  and  the  fruits  themselves  have 
been  identified. 

Vegetation  of  the  coal  period. — The  most  exuberant 
vegetation  appears  to  have  been  that  of  the  coal  period, 
and  its  entombed  treasures  now  supply  the  world  with  fuel, 
especially  in  countries  where  the  forests  are  exhausted,  or 
where  economy  of  the  modern  vegetation,  or  preference  for 
the  results  of  the  ancient,  decides  the  choice. 

Varieties  of  the  ancient  fossil  vegetation. — The  ancient 
vegetation  appears  in  many  forms,  as  in  that  of  lignite  of 
coal,  and  of  silicious,  calcareous,  and  ferruginous  petrifac- 
tions, still  preserving  the  peculiar  structure ;  and  this  has 
been  made  still  more  distinct  and  satisfactory,  by  cutting 
slices  of  the  petrified  trunks,  and  grinding  them  down 
until  they  become  so  thin  as  to  be  transparent,  when  the 
microscope  reveals  the  internal  arrangement  of  the  pores 
and  fibres,  which  characterises  the  family.  Thus,  it  has 
been  made  to  appear  that  various  species  of  coniferous  trees 
preceded  the  coal  formation  in  the  south  of  Scotland,  and 
the  north  of  England,  and  that  zamias,  and  other  palm-like 
trees,  preceded  the  chalk  in  the  south  of  England.  No 
species  of  the  ancient  world  is  identical  with  any  one  of 
the  modern,  and,  as  has  been  already  remarked,  the  early 
vegetation  implies,  generally,  a  warm  and  moist  climate, 
and  great  fertility  of  production. 

stquatic  animals  —  reptiles.  —  Animals,  almost  exclu- 


sively  marine,  attest  the  great  prevalence  of  the  ocean  in 
the  earlier  geological  periods,  and  it  is  not  until  we  have 
passed  the  coal  in  the  ascending  order,  that  we  begin  to 
find  reptiles  of  marine  or  of  amphibious  families,  and 
ultimately,  still  higher  up,  of  terrestrial  races.  With 
a  similarity  of  type  to  the  families  of  the  present  day, 
both  their  genera  and  species  are,  however,  without  a 
single  perfect  copy  in  modern  times.  Some  were  carni- 
vorous, and  swam  in  the  shallow  seas,  estuaries,  lagoons, 
and  bays,  and  preyed  upon  fishes,  molluscous  animals,  and 
each  other;  some  lived  on  land,  and  were  herbivorous;  and 
although  a  few  species,  the  megalosaurus  and  iguanodon, 
for  example,  were  colossal  in  size,  and  terrible  in  form,  it 
is  probable  that  the  latter  of  these  terrestrial  saurians  was 
harmless  and  inoffensive,  while  the  tooth  of  the  megalo- 
saurus would  indicate  a  ferocious  animal  of  prey,  like  the 
marine  saurians.  Bones  of  many  genera  and  species  of 
the  reptile  tribes,  especially  the  saurians,  have  been  found, 
and  of  some  individuals,  entire,  or  nearly  perfect 
skeletons; — among  them,  those  of  vast  dimensions  have 
been  discovered,  inclosed  in  the  solid  rocks,  along 
with  their  petrified  and  half-digested  food,  and  with  their 
coprolites. 

Marsupial  animals. — If  the  reptiles  formed  the  transition 
from  the  marine  animals  upward — the  marsupials,  as  they 
are  called,  were  the  link  between  the  ancient  reptiles  and 
terrestrial  quadrupeds.  The  marsupials,  of  which  the 
opossum  is  an  example,  receive  their  young  (which, 
although  born,  are  still  only  immature)  into  an  exterior 
pouch,  or  abdominal  sack,  and  there  nourish  them  at  their 
paps,  until  they  are  fitted  to  go  abroad,  and  to  encounter  the 
vicissitudes  of  their  peculiar  modes  of  life.  These  are  the 
only  animals  hitherto  found  below  the  chalk  which  ap- 
proximate to  the  proper  terrestrial  character.  Dr.  Mantell 
has,  however,  found  the  bones  of  birds,  in  the  wealden 


29 

beneath  the  chalk;  and  Prof.  Hitchcock  has  discovered 
numerous  tracts  of  animals,  believed  to  be  those  of  birds, 
and  perhaps  of  reptiles,  some  of  them  of  gigantic  dimen- 
sions, in  the  new  red  sandstone  of  the  Connecticut  River. 

Fossils  of  the  chalk  and  tertiary. — The  chalk  follows, 
with  its  immense  and  varied  marine  treasures ;  and  next 
the  lower  tertiary,  still  marine,  succeeded  by  the  middle 
tertiary,  where  proper  and  fully  characterised  terrestrial 
animals  are  first  found.  Through  the  remaining  beds  of 
tertiary,  both  marine  and  fresh  water,  we  find  molluscous 
animals,  fishes,  reptiles,  and  vegetables,  verging  towards, 
and  even  identical  with  those  of  our  own  times ;  and  occa- 
sionally we  discover  also  terrestrial  animals,  but  still  different 
from  the  modern,  until,  at  last,  in  the  diluvium  and  allu- 
vium, and  the  most  recent  sedimentary  and  concretionary 
formations,  we  discern  animals  and  plants  still  more  and 
more  like  those  now  living,  and  finally  graduating  into 
perfect  identity  with  existing  races. 

Man  nowhere  fossil. — Man  and  his  works  appear  only 
in  the  last  stages,  associated  with  the  remains  of  just  such 
beings  as  now  exist,  both  in  the  animal  and  vegetable 
world.  The  pages  of  our  author  will  disclose  the  great 
variety  and  extraordinary  form,  and,  in  many  cases,  colossal 
dimensions,  unrivalled  at  the  present  time,  of  some  of  the 
ancient  animals,  the  megatherium,  sivatherium,  dinothe- 
rium,  mastodon,  elephant,  hippopotamus,  rhinoceros,  the 
cavern  bear,  tiger,  and  many  others.  In  consequence  of 
the  most  recent  discoveries  of  geology,  we  are  hurried  from 
that  which  is  stupendous  and  vast,  to  that  which  is  incon- 
ceivably minute.  The  extremes  of  creation  meet  in  the 
mineral  kingdom.  In  the  solid  rocks  are  found  both  the 
colossal  reptiles,  and  the  microscopic  infusorial  animalculae. 
Ehrenberg  has  discovered  that  polishing  slate  is  made  up 
of  animalculae  so  minute,  that  forty-one  thousand  millions 
of  them  are  required  to  fill  a  cubic  inch,  in  every  grain  of 


30 

which  there  are  one  hundred  and  eighty-seven  millions, 
and  their  silicious  shields  are  the  cause  of  the  well-known 
effect  of  the  tripoli,  or  rotten  stone,  in  polishing  steel,  &c. 
An  analogous  constitution  has  been  discovered  in  flint, 
opal,  and  bog-iron,  and  the  deposits  of  our  modern  peat 
bogs  in  this  country,  are  filled  with  similar  animalcules, 
the  figures  of  some  of  which  have  been  given  by  Prof. 
Baily,  in  the  American  Journal  of  Science,  vol.  xxxv. 
p.  118. 

10.  GENERAL  REMARKS.— Such  is  an  exceedingly  gene- 
ral and  very  imperfect  sketch  of  the  progressive  creation 
of  animals  and  plants;  that  have  inhabited  our  world — have 
become  extinct,  and  are,  in  countless  myriads,  entombed  in 
the  rocky  strata,  and  in  the  solid  mountains.  It  is  only  on 
the  upper  surface  that  we  discover  loose  and  scattered  ruins, 
either  in  the  soil,  or  buried  in  the  masses  of  gravel,  sand, 
and  clay;  ruins  of  rocks,  and  fragments  of  strata,  along 
with  the  relics  of  animals,  trees,  and  other  superficial  de- 
posits, such  as  we  could  in  any  reason  attribute  to  the 
catastrophe,  or  catastrophes,  of  rising  and  rushing  water, 
the  deluges  of  geologists,  or  the  deluge  of  the  Scriptures; 
the  latter,  almost  alone,  being  admitted  to  the  contempla- 
tions of  those  who  are  uninstructed  in  our  science.  Now, 
it  is  a  matter  of  physical  demonstration,  that  the  earth 
existed  for  many  ages  before  man  was  called  into  being. 
The  whole  course  of  geological  investigation  proves  this 
view  to  be  the  only  one  that  ia  consistent  with  the  facts. 
To  be  convinced  of  its  truth,  it  is  only  necessary  to  become 
thoroughly  acquainted  with  the  records  of  a  progressive 
creation  and  destruction  which  the  earth  contains,  inscribed 
on  medals,  more  replete  with  historical  truth,  and  more 
worthy  of  confidence,  than  those  that  have  been  formed  by 
man ;  as  much  more  as  nature  exceeds  in  veracity  the 
erring  or  mendacious  records  of  the  human  race. 

11.    CONSISTENCY    OF    GEOLOGY   WITH   THE    SCRIPTURE 


31 

HISTORY. — Hardly  two  centuries  have  passed  since  the 
astronomy  of  Galileo,  Kepler,  and  Newton,  was  regarded 
as  inconsistent  with  the  Scriptures,  and  therefore  heretical; 
and  although  the  discrepancy  of  the  literal  meaning  of  the 
Bible  with  the  real  truths  of  astronomy,  is  still  as  great  as 
ever,  no  one  any  longer  hesitates  to  regard  astronomy  as 
giving  a  just  view  of  the  stupendous  mechanism  of  the 
heavens ; — all  agree  in  understanding  the  language  of  the 
Scriptures  as  being  adapted  to  the  appearances  of  the  hea- 
vens, of  which  alone  mankind  in  general  can  form  any 
just  conception,  and  with  which  alone  the  Scriptures  are 
concerned.  The  Bible  being  designed  as  a  code  of  moral 
instruction,  as  a  revelation  of  a  future  life,  and  of  the 
sanctions  that  belong  to  that  momentous  subject,  contains 
no  systems  of  science.  Moral  science,  essentially  con- 
tained in  the  Scriptures,  is  not,  even  there,  presented  in  a 
regular  form,  as  in  human  systems,  but  in  modes  more 
happily  adapted  to  the  actual  condition  and  capabilities  of 
mankind. 

In  relation  to  physics,  the  information  contained  in  the 
Bible  is  only  incidental.  God  is  declared  to  be  the  Creator 
of  the  heavens  and  the  earth, — the  physical  universe, — 
and  throughout  the  sacred  volume,  there  are  innumerable 
allusions  to,  and  illustrations  of  his  character,  as  its  Creator 
and  Governor,  but  there  is  not  even  the  most  general  out- 
line of  any  physical  science ;  the  creation  of  the  heavens 
and  the  earth,  of  the  sun  and  the  moon,  being  disposed  of 
with  extreme  brevity,  while  the  allusions  to  the  geological 
arrangements  of  this  planet  are  only  such  as  are  connected 
with  the  first  appearance  of  its  organized  beings,  and  the 
emergence  of  the  land  from  the  original  ocean. 

Instruction  in  the  sciences  was  not  the  object  of  the 
Scriptures :  the  physical  creation  was  left  by  the  Divine 
Author  for  the  delightful  exercise  of  our  faculties,  an  inex- 
haustible source  of  mental  and  moral  pleasure ;  for  appli- 


32 


cation  to  use,  to  increase  me  power  and  the  comforts  of 
man  ;  for  the  additional  illustration  of  the  character  of  God, 
and  also  for  an  exhaustless  fountain,  whose  streams  mingle 
harmoniously  with  those  of  divine  revelation. 

From  the  study  of  the  physical  creation,  man  has  there- 
fore drawn  all  the  physical  sciences,  of  which  astronomy 
is  the  most  sublime  and  splendid,  while  geology  yields,  in 
this  respect,  only  to  astronomy.  Neither  astronomy  nor 
geology  is,  however,  taught  in  the  Scriptures,  but  both 
are  contained  in  nature,  and  their  astonishing  truths  have 
been  brought  to  light  by  human  research. 

While,  as  already  remarked,  astronomy  is,  in  fact,  incon- 
sistent with  the  apparent  movements  in  the  heavens,  and, 
therefore,  with  the  literal  and  popular  phraseology  of  the 
Scriptures,  which  allude  to  physical  things  as  they  appear, 
and  not  as  they  are  in  reality, — geology  presents  not  even 
a  literal  discrepancy,  but,  on  the  contrary,  a  substantial 
agreement  in  its  facts  with  the  Scriptures :  the  latter  de- 
scribe a  physical  creation  of  mineral  matter,  and  a  succes- 
sive creation  of  plants  and  animals,  ending  with  man,  while 
geology,  by  irrefragable  demonstrations,*  which  nothing  but 
a  study  of  the  earth  could  afford,  proves  this  history  to  be 
true.  The  Scriptures  describe  a  universal  deluge,  and 
geology  proves  that  every  part  of  the  earth  is  marked  by 
the  effect  of  such  visitations,  occurring  at  one  time,  or  at 
many  times ; — a  repetition  of  local  deluges,  or  a  general 
one,  would  produce  similar  results ;  and  although  it  may 
be  impossible  to  distinguish  between  the  accumulated 
effects  of  local  overflows,  and  a  general  diluvial  devasta- 
tion, the  surface  of  the  earth  abounds  with  diluvial  ruins. 
The  Scriptures  declare  that  there  was  a  beginning,  and 
geology  proves  that  there  was  a  time  when  plants,  and 
animals,  and  man,  did  not  exist ;  both  the  Scriptures  and 

*  See  Dr.  Buckland's  Bridgewater  Treatise,  an  admirable  and  per- 
fectly conclusive  moral  and  physical  demonstration. 


geology  arc  silent  as  to  the  period  when  the  fiat  of  the 
Creator  called  our  earth  and  the  planetary  systems  into 
being.  It  was,  doubtless,  in  very  remote  antiquity,  but  the 
beginning  is  known  only  to  Him  who  has  neither  beginning 
of  years  nor  ending  of  days. 

Having  elsewhere  discussed  the  question  of  the  duration 
of  the  days,*  and  of  the  creation,  we  shall  not  here  reite- 
rate those  arguments,  satisfied  that  the  date  of  the  begin- 
ning is  not  recorded  either  in  nature  or  in  revelation,  and 
may  extend  back  to  any  period,  however  long,  which  phy- 
sical truth  may  demand.  On  the  other  hand,  the  moral 
dispensations  of  God  to  our  world,  necessarily  begin  with 
man,  and  the  account  of  him  which  is  contained  in  the 
Bible  is  fully  confirmed  by  his  uniform  character,  as 
exhibited  by  all  tradition  and  history.  While,  therefore, 
geology  proves  that  our  world  existed  for  many  ages  before 
man  was  created,  and  that  his  creation  was  only  the  last 
act  in  the  series,  it  perfectly  concurs  in  the  conclusion  that 
the  human  race  cannot  have  been  on  the  earth  more  than 
a  few  thousand  years.  Where  then  is  the  discrepancy 
between  geology  and  the  sacred  history,  and  what  is  the 
cause  that  this  science  fills  many  minds  with  alarm,  and 
not  a  few  with  hostility?  As  the  result  of  no  short  or 
superficial  study,  or  light  contemplation,  we  aver,  with 
perfect  confidence,  that  the  alarm  is  without  cause — the 
hostility  without  justification ;  and  equally  baseless  are  the 
hopes  of  those  who  would  draw  from  geology,  weapons 
with  which  to  assail  the  Scriptures.  This  science,  like 
her  elder  sister,  astronomy,  is  the  ally,  and  not  the  enemy 
of  revealed  truth.  The  consistency  of  geology  with 
the  Scripture  history,  is  susceptible  of  a  perfect  and 
triumphant  defence,  but  it  is  not  found  in  the  refinements 
of  exegesis,  nor  in  the  forced  solution  of  a  general  deluge, 

*  Appendix  to  the  second  and  third  American  editions  of  Bakewell's 
Geology. 

d 


34 

entirely  unsatisfactory,  and  indeed  impossible,  as  a  cause 
of  the  regular  formations  of  the  earth,  immensely 
varied  as  they  are,  and  exuberant  in  the  relics  of  many 
successive  races  of  the  animals  and  vegetables  of  past  ages. 
But  this  consistency  is  found  in  the  regular  induction  from 
facts,  in  the  just  understanding  of  time,  and  in  its  exten- 
sion back  beyond  the  creation  of  man,  so  far  as  to  cover 
the  innumerable  events  that  have  certainly  happened. 
To  this  conclusion  the  religious  world  is  fast  approaching ; 
its  arrival  at  the  goal  of  truth  is  as  certain  as  the  progress 
of  time,  and  the  period  is  near  at  hand  when  the  great 
deductions  of  geology,  like  those  of  astronomy,  will  be 
viewed  as  in  perfect  harmony  with  the  Scriptures,  and  as 
highly  illustrative  of  the  character  of  the  great,  glorious, 
and  beneficent  Being,  who  in  the  beginning  created  the 
heavens  and  the  earth.  The  time  has  already  come,  when 
those  who  claim  to  judge  of  the  consistency  of  the  Scrip- 
tures with  geology,  must  study  this  science,  not  superficially, 
but  profoundly ;  for  in  no  other  way  can  they  become 
qualified  to  form  a  just  opinion  in  the  case.  It  is,  indeed, 
lamentable  to  observe  the  crude  and  absurd  speculations 
of  some,  who  speak  and  write  in  a  manner  adapted  only 
to  expose  their  own  entire  ignorance  of  the  subject ;  and 
there  are  not  wanting  those,  both  at  home  and  abroad, 
whose  arrogance  and  censoriousness  are  exhibited  in  a 
manner  equally  uncandid  and  undignified ;  while  their 
incredulity,  manifested  by  a  blind  rejection  of  evidence 
without  examination,  (a  real  infidelity,)  would  imply,  that 
the  Author  of  nature  has  given  a  revelation  inconsistent 
with  the  work  of  his  own  hands.  We  regard  with  kind- 
ness and  forbearance  those  whose  honest  fears,  tempered 
by  a  spirit  of  candour,  would  be  removed  by  an  accurate 
knowledge  of  geological  facts,  but  geologists  have  a  right 
to  claim  that  critics,  whose  decisions  are  made  without 
any  adequate  examination  of  the  science,  shall  abstain  from 


imputations  on  those  who  faithfully  study  and  report  th 
actual  structure  of  the  earth,  and  who  reason  upon  the 
facts  according  to  the  soundest  principles  of  logical  and 
philosophical  induction.  Geologists  do  not,  in  turn,  invade 
the  domain  of  criticism,  nor  is  there  the  least  occasion  to 
do  so ;  for  they  receive  language  in  its  usual  acceptation, 
and  as  it  is  expounded  hy  those  who  are  the  hest  qualified 
to  judge  ;  still,  they  assume  the  liberty  to  understand  it  in 
consistency  with  the  subject  to  which  it  is  applied — in 
consistency  with  the  truths  of  nature,  which  are  as  irre- 
fragable as  those  of  revelation,  for  they  proceed  from  the 
same  Author,  and  are  incapable  of  perversion.  In  the 
beautiful  language  of  Professor  Sedgwick — "  No  opinion 
can  be  heretical  but  that  which  is  not  true.  Truths  can 
never  war  against  each  other.  We  have  nothing  to  fear 
from  the  results  of  our  inquiries,  provided  they  be  followed 
in  the  laborious,  but  secure  road  of  honest  induction.  In 
tins  way  we  may  rest  assured,  we  shall  never  arrive  at 
conclusions  opposed  to  any  truth,  either  physical  or  moral, 
from  whatever  source  this  truth  may  be  derived ;  nay 
rather  that  new  discoveries  will  ever  lend  support  and 
illustration  to  things  which  are  already  known,  by  giving 
a  larger  insight  into  the  universal  harmonies  of  nature."* 
It  is  most  unwise  then  to  reject  truth,  for  which  science 
is  indeed  but  another  name,  and  it  is  quite  certain  that 
the  friends  of  revelation,  and  the  friends  of  science,  may 
walk  harmoniously  together,  for  they  are  cultivating  only 
different  departments  of  the  same  great  field ;  the  fruits 
which  they  gather  may  be  safely  stored  in  the  same 
garner,  and  in  all  coming  ages,  will  be  wisely  regarded  as 
treasures  of  inappreciable  value. 

12.  NOTICE  OF  THIS  WORK  AND  ITS  AUTHOR. — /We  shall 
conclude  by  an  immediate  reference  to  the  work  before  us, 
satis-lied  if  our  remarks  shall  serve  to   draw  attention  to 
*  Address  to  the  London  Geological  Society,  Feb.  19,  1830. 


36 

these  beautiful  and  instructive  lectures,  and  to  their  dis- 
tinguished author. 

Dr.  Mantell's  earlier  publications,  among  which  were 
"  Illustrations  of  the  Geology  of  Sussex,"  4to ;  also  a  work 
on  the  "Fossils  of  Tilgate  Forest,"  4to,  and  "The  Geo- 
logy of  the  South-east  of  England,"  8vo ;  all  with  nume- 
rous plates  and  cuts,  and  many  memoirs  and  tracts,  appeared 
when  the  author  resided  in  his  native  town  of  Lewes, » 
seven  miles  from  Brighton.  By  his  great  industry  and 
zeal,  he  redeemed  from  the  cares  of  an  extensive  and 
laborious  medical  practice,  time  to  produce  these  fine  works, 
which  rank  with  the  very  first  on  the  science  of  geology,  and 
have  raised  the  reputation  of  their  author  to  a  high  standard. 
Dr.  Mantell,  during  his  residence  at  Lewes,  collected  a 
splendid,  and  in  a  great  measure  unique  museum  of  organic 
remains,  the  most  remarkable  of  which  were,  the  astonish- 
ing bones  and  other  reliquiae  of  his  own  region,  discovered 
entirely  by  himself,  f 

A  few  years  since,  he  removed  to  Brighton,  and  there 
established  his  museum  in  an  appropriate  mansion.  It 
soon  became  the  nucleus  for  a  Sussex  Scientific  and  Literary 
Institution,  and  in  its  rooms  were  held  instructive  and 
entertaining  conversaziones.  On  these  occasions,  and  in 
connexion  with  the  museum,  many  interesting  objects  of 
nature  and  art  were  exhibited  and  described  by  Dr.  Man- 
tell  and  his  friends,  to  the  fashionable  and  noble  crowd 
which  revolve  around  the  British  court,  during  its  tem- 
porary pilgrimage  to  this  favourite  spot  on  the  chalky 
shores  of  Albion. J 

Here  Dr.  Mantell  yielded  to  the  wishes  of  his  friends 
and  the  public,  by  giving  occasional  lectures  on  the 

*  la  Sussex,  Eugland;  50  miles  from  London. 

t  See  American  Journal  of  Science;  vol.  xxiii.  p.  162;  and  Descriptive 
Catalogue  of  the  Mantellian  Museum,  8vo.  with  plates. 
I  Fifty-five  miles  south-east  of  London,  on  the  Channel  coat>t. 


37 

subjects  which  he  had  so  successfully  cultivated.  Those 
who  had  read  his  various  works,  in  which  science,  genius, 
and  taste,  were  warmed  by  a  noble,  but  disciplined  and 
sustained  enthusiasm,  were  gratified  to  find  that  his  powers 
as  a  public  speaker  were  commensurate  with  his  high 
attainments  as  an  original  investigator,  and  with  his  repu- 
tation as  a  man  of  science,  and  of  intellectual  vigour.  His 
success  in  this  character  was  fully  equal  to  his  previous 
reputation.  In  consequence,  he  was  called  upon  to  give 
a  regular  course  of  lectures  on  geology  and  the  connected 
sciences,  aided  by  his  magnificent  museum,  and  by  ample 
illustrations  from  drawings. 

The  WONDERS  OF  GEOLOGY  contain  the  substance 
of  the  lectures  delivered  by  Dr.  Mantell  at  Brighton. 
The  title  is  appropriate,  but  it  would  be  great  injustice  to 
consider  this  work  as  a  mere  collection  of  mirabilia.  It 
embraces,  in  truth,  a  regular  system  of  geology,  exhibiting 
its  leading  facts,  and  clearly  elucidating  its  philosophy, 
which  is  the  great  object  of  the  work. 

The  arrangement  is  from  the  modern  to  the  most  ancient, 
or  from  the  alluvial  and  diluvial,  down  through  the  ter- 
tiary, secondary,  and  transition,  to  the  primary  rocks,  and 
all  the  igneous  formations ;  ending  with  the  actual  igni- 
vomous  mouths,  as  they  appear  in  the  existing  volcanos. 

Commencing  with  the  human  epoch,  he  proceeds 
through  the  various  formations  which  preceded  the  creation 
of  man ;  and  the  several  eras  of  the  tertiary,  the  chalk, 
the  weald,  the  oolite  and  lias,  the  carboniferous  strata, 
and  the  primary  rocks,  are  by  turns  the  subject  of  instruc- 
tive and  eloquent  comment.  The  work  is  illustrated  with 
much  taste  ;  a  frontispiece,  by  the  celebrated  British  painter 
Martin,  gives  a  representation  of  the  country  of  the  Igua- 
nodoii,  representing  the  monsters  of  the  ancient  world  attack- 
ing and  devouring  each  other ;  two  drawings  of  corals,  by 
Miss  Mantell,  form  embellishments  of  first-rate  beauty  and 


38 


interest ;  and  more  than  a  hundred  wood  engravings,  with 
coloured  sections  of  strata,  maps,  &c.,  bestow  at  once  pic- 
torial grace  and  scientific  illustration  on  the  volumes.  A 
work  of  this  kind  comprises  a  vast,  an  almost  unlimited 
field  of  inquiry,  and  requires  in  the  writer  who  should  do 
justice  to  the  subject,  qualifications  and  powers  of  no 
common  character. 

Thus  much  of  the  order ;  now  of  the  execution  of  the 
WONDERS  OF  GEOLOGY.  In  point  of  science  it  is  precise, 
accurate,  condensed,  and  cumulative  in  proof,  conducting 
the  pupil  forward  by  a  series  of  steps,  grateful  in  the  pro- 
gress, and  conclusive  in  the  result.  The  style  is  lucid  and 
elevated,  while  the  figures  render  every  thing  intelligible, 
even  to  the  unscientific  reader.  The  introduction  which 
precedes,  and  the  retrospect  which  closes  each  lecture, 
afford  an  admirable  summary  both  of  facts  and  doctrine, 
and  are  distinguished  by  eloquent  diction  and  comprehen- 
sive views.  As  the  greatest  recommendation  of  Dr. 
Mantell's  work,  we  would  remark,  that  it  is  an  excellent 
pioneer  and  conductor  for  the  pupil  attending  a  course  of 
lectures,  and  even  for  the  private  student,  who  has  to  work 
his  own  way  without  a  guide.  In  both  these  respects,  it  is 
superior  to  any  look  with  which  we  are  acquainted,  and  we 
are  gratified  in  having  it  in  our  power  to  introduce  it  to  the 
American  public  under  a  form  in  which  it  can  reach  the 
colleges,  academies,  and  schools — not  to  mention  the  studies 
of  literary  men,  and  the  parlours  of  families.  It  is  a  book 
of  delightful  entertainment  as  well  as  of  instruction,  and 
although  less  elaborate  than  the  original  works  of  investi- 
gation of  the  same  author,  will  find  its  way  to  many  more 
readers,  and  will,  therefore,  be  even  more  extensively  useful 
than  they  have  been. 

The  author  modestly  disclaims  the  merit  of  originality, 
but  the  scientific  world  will  not  forget  that  his  own  original 
investigations  have  been  among  the  moat  successful  of  the 


nge,  and  their  results  among  the  most  brilliant  obtained  by 
geoiogufe.* 

The  present  work,  like  others  of  the  same  author,  is  dis- 
tinguished by  a  reverend  spirit  towards  the  Author  of 
nature,  who  appears  to  be  sometimes  forgotten  by  those 
who  investigate  his  works,  while  Dr.  Mantell's  volumes 
will  leave  a  happy  moral  and  religious  impression  upon  the 
minds  of  young  persons. 

It  is  an  interesting  fact  that  among  the  fine  writers  of 
the  present  day,  several  of  the  geologists  hold  a  very  high 
rank,  and  their  works,  although  devoted  to  science,  are  also 
an  ornament  to  literature.  Who  can  write  better  than 
Sedgwick,  Buckland,  Lyell,  Daubeney,  Murchison,  De  La 
Beche,  Mantell,  and  many  other  geologists  who  might  be 
named  ? 

There  is  but  one  painful  impression  left  on  the  mind,  in 
closing  Dr.  Mantell's  volumes.  He  informs  us  that  this  is 
his  farewell  to  science,  f  as  he  must  henceforth  be  solely 
devoted  to  his  arduous  profession,  and  for  this  purpose  he  has 
already  left  the  classical  fields  of  his  own  geological  domain — 
Tilgate  Forest  and  Brighton  cliffs,  and  the  South  Downs  of 
Sussex — to  plant  himself  in  a  suburban  village  of  the  metro- 
polis,]: as  a  practising  surgeon  and  physician.  We  are  thus 
reminded  of  Blackstone's  farewell  to  the  Muses,  when  he 
was  about  to  enter  the  gloomy  halls  of  the  courts  of  law; 
and  still  more  forcibly,  of  the  struggle  of  Garrick  between 
Comedy  and  Tragedy,  as  portrayed  by  the  magic  pencil  of 
Reynolds — each  rival  sister  wooing  him  with  admitted  and 
almost  prevailing  attractions.  In  the  present  contest  be- 
tween medicine  and  science,  each  striving  to  appropriate 

*  The  gold  Wollaston  medal  of  the  .Geological  Society  of  London 
was  awarded  to  Dr.  Mantell  for  his  discoveries  in  the  Wealden  of  the 
South-east  of  England. 

t  At  least  as  a  lecturer. 

t  Clapham  Common,  Surrey,  three  miles  from  London. 


40 


to  itself  an  honoured  votary,  we  dare  avow  that  our  loyalty 
is,  at  all  hazards,  engaged  in  favour  of  geology ;  and  we 
cannot  but  express  our  deep  regret,  that  a  man  who  has 
done  honour  to  the  British  nation,  and  delighted  the  scien- 
tific world  hy  his  beautiful  researches,  should  not  be  made 
easy  to  pursue  the  bent  of  his  own  glowing  and  highly- 
gifted  mind,  and  thus  to  work  onward  in  science  until  the 
labour  of  life  is  done !  In  conclusion  we  lament  to  add,  that 
from  the  death  of  the  noble  patron  of  the  Sussex  Institution, 
the  Earl  of  Egremont,  and  the  supineness  of  some,  and  the 
opposition  of  others  of  its  members,  Dr.  Mantell  has  been 
compelled  to  abandon  the  lowg-cherished  hope  of  establish- 
ing a  county  museum  in  his  native  province,  and  the 
"  Mantellian  Museum  "  is  now  removed  to  the  British 
Museum  ;  Sussex,  to  the  disgrace  of  its  wealthy  inhabitants, 
being  thus  deprived  for  ever  of  that  invaluable  collection  of 
the  natural  records  of  its  physical  history. 


THE 

WONDERS    OF    GEOLOGY. 
LECTURE  I. 

.   Introductory  remarks.      2.    Importance  of  geology.      3.    Nature  of 
geology.     4.  Harmony  between  revelation  and  geology.     5.  Extent 
of  geological  epochs.     6.  Object  of  the  lectures.    7.  Physical  struc- 
ture of  the  earth.      8.    Geographical  distribution  of  animals  and 
vegetables.    9.  Temperature  of  the  earth.    10.  Nature  of  the  crust  of 
the  globe.     11.  Composition  of  the  rocks  and  strata.    12.  Classification 
of  rocks.     13.  Primary  rocks.    14.  Transition  strata.     15.  Secondary 
strata.     16.  Tertiary  strata.     17.  Alluvial  deposits.     18.  Geological 
mutations.    19.  Connexion  of  geology  with  astronomy.    20.  Nebular 
theory  of  the  universe.    21.  Different  states  of  nebulae.   22.  Formation 
of  the  solar  system.    23.   Gaseous  state  of  the  earth.    24.  Geology 
illustrated  by  astronomy.     25.   Meteorites.    26.  Mrs.  Somerville  on 
meteorites.      27.    Origin    of  meteorites.     28.    Existing    geological 
changes.    29.  Effects  of  streams  and  rivers.    30.  Delta  of  the  Ganges 
and  Mississippi.    31.  Formation  of  strata.     32.  Rippled  sand.    33. 
Lewes  levels.    34.  Remains  of  man  in  modern  alluvium.    35.  Peat 
bogs.    36.  Conversion  of  peat  into  coal.    37.  Subterranean  forests. 
38.  Geological  effects  of  the  sea.    39.  Bed  of  the  ocean.    40.  Currents 
and  their  effects.     41.    Incrusting  springs.     42.   Incrustations  not 
petrifactions.     43.  Lake  of  Solfatara.     44.   Marble  of  Tabreez.    45. 
Stalactites  and  stalagmites.    46.   Grotto  of  Antiparos.    47.  Consoli- 
dation of  sand  and  loose  materials.  48.  Destruction  of  rocks  by  carbonic 
acid.    49.  Carbonic  acid  gas  in  caverns  and  wells.    50.  Consolidation 
of  loose  strata  by  iron,     51.  Recent  formation  of  marine  limestone 


THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

in  the  Bermudas.  52.  Fossil  human  skeletons  of  Guadaloupe.  53. 
Impressions  of  human  feet  in  sand-stone.  54.  Isle  of  Ascension. 
55.  Drifted  sand.  56.  Sand-flood  and  recent  limestones  of  Cornwall. 
57.  Silicious  deposits.  58.  The  Geysers.  59.  Hertfordshire  con- 
glomerate, or  pudding-stone.  60.  Effects  of  high  temperature.  61. 
Volcanic  agency.  62.  Expansion  of  rocks  by  heat.  63.  Temple  of 
Jupiter  Serapis.  64.  Elevation  of  the  coast  of  Chili.  65.  Lifted  sea 
beach  at  Brighton.  66.  Elevation  of  Scandinavia.  67.  Retrospect. 


1.  INTRODUCTORY  REMARKS.  —  It  has  been  ob- 
served by  a  distinguished  divine,*  that  in  order  to 
obtain  a  proper  sense  of  the  interest  and  importance 
of  any  science,  and  of  the  objects  which  it  embraces, 
nothing  more  is  necessary  than  the  intent  and  per- 
severing study  of  them ;  and  that  such  is  the  con- 
summate perfection  of  all  the  works  of  the  Creator, 
that  every  inquirer  will  discover  a  surpassing  worth, 
and  grace,  and  dignity,  in  that  especial  department 
of  knowledge  to  which  he  may  peculiarly  devote 
his  attention.  Whatever  walk  of  philosophy  he 
may  enter,  that  will  appear  to  him  the  path  which 
is  the  most  enriched  by  all  that  is  fitted  to  captivate 
the  intellect,  and  to  excite  the  imagination.  Yet 
before  we  can  attain  that  elevation  from  which  we 
may  look  down  upon  and  comprehend  the  mysteries 
of  the  natural  world,  our  way  must  be  steep  and 
toilsome,  and  we  must  learn  to  read  the  records  of 
creation  in  a  strange  language.  But  when  this 
knowledge  is  once  acquired  it  becomes  a  mighty 
instrument  of  thought,  enables  us  to  link  together 
the  phenomena  of  past  and  future  times,  and  gives 

*  Professor  Sedgwick. 


§  2,  3.  NATURE  OF  GEOLOGY.  3 

the  mind  a  domination  over  many  parts  of  the  natural 
world,  by  teaching  it  to  comprehend  the  laws  by 
which  the  Creator  has  ordained  that  the  actions  of 
material  things  shall  be  governed. 

2.  IMPORTANCE   OF   GEOLOGY. — In    the   whole 
circle  of  the  sciences,  there  is  perhaps  none  that 
more  strikingly  illustrates  the   force   and  truth  of 
these  remarks,  than  Geology ;  none  which  offers  to 
its  votaries  rewards  so  rich,  so  wondrous  and  in- 
exhaustible.    In  the  shapeless  pebble  that  we  tread 
upon,  in  the  rude  mass  of  rock  or  clay,  the  un- 
instructed  eye  would  in  vain  seek   for  novelty  or 
beauty ;   like  the  adventurer  in  Eastern  fable,  the 
inquirer  finds  the  cavern  closed  to  his  entrance,  and 
the  rock  refusing  to  give  up  the  treasures  entombed 
within  its  stony  sepulchre,  till  the  talisman  is  ob- 
tained  that   can   dissolve    the   enchantment,    and 
unfold  the  marvellous  secrets  which  have  so  long 
lain  hidden. 

3.  NATURE  OF  GEOLOGY. — To  the  mind  which 
is   unacquainted   with   the    nature  and   results   of 
geological   inquiries,    and  which    has  been  led  to 
believe  that  the  globe  we  inhabit  is  in  the  state 
in  which  it  was  first  created,   and  that  with  the 
exception  of  the  effects  of  a  general  deluge,  its 
surface  has  undergone  no  material  change,   many 
of  the  facts  to  be  noticed  in  the  course  of  these 
lectures  may  appear  almost  incredible,  and  the  in- 
ferences deduced  from  their  investigation  be  con- 
sidered as  the  vagaries  of  the  imagination  rather 

B2 


4  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

than  the  legitimate  inferences  of  sound  philosophy. 
If,  therefore,  it  be  absolutely  necessary,  as  it  un- 
questionably is,  that  in  the  pursuit  of  knowledge 
of  any  kind,  before  even  experience  can  be  em- 
ployed with  advantage,  we  must  dismiss  from  our 
minds  all  prejudices,  from  whatsoever  source  they 
may  arise,  this  mental  purification  becomes  the 
more  indispensable  in  a  science  like  Geology,  in 
which  we  meet  at  the  very  threshold  with  facts  so 
novel  and  astounding;  teaching  us,  that  although 
man  and  other  living  things  be,  as  it  were,  but  the 
creation  of  yesterday,  the  earth  has  teemed  with  num- 
berless forms  of  animal  and  vegetable  life,  myriads  of 
ages  ere  the  existence  of  the  human  race. 

Geology  may  be  termed  the  physical  history  of 
the  earth, — it  comprehends  the  investigation  of  its 
structure,  and  the  characters  and  causes  of  the 
various  changes  which  have  taken  place  in  the 
organic  and  inorganic  kingdoms  of  nature.  It  has 
been  emphatically  called,  by  one  of  our  most  emi- 
nent philosophers,  the  sister  science  of  Astronomy. 
But,  relating  as  it  does  to  the  history  of  the  past, 
and  carrying  us  back,  by  the  careful  examination  of 
the  relics  of  former  ages,  to  periods  so  remote  as  to 
startle  all  our  preconceived  opinions  of  the  age  of  our 
globe,  the  fate  of  its  early  cultivators  has  resembled 
that  of  the  immortal  Galileo  and  the  astronomers 
of  his  time  ;  and  for  a  similar  reason,  namely,  the 
supposed  discrepancy  between  the  discoveries  and 
inferences  of  science,  and  the  Mosaic  cosmogony. 


§  4.  HARMONY  WITH  REVELATION.  '> 

4.  HARMONY  BETWEEN  REVELATION  AND  GEO- 
LOGY.— There  was  a  time  when  every  geologist  was 
required  to  defend  himself  against  imputations  of 
this  kind,  and  I  deeply  regret  to  find  that  there  still 
exists  in  the  minds  of  many  well-meaning  persons 
a  prejudice  against  the  study  of  Geology,  from  a 
mistaken  apprehension,  lest  it  should  weaken  our 
belief  in  the  revealed  word  of  God  ;  for  they  assume 
that  a  discrepancy  must  exist  between  the  results  of 
geological  inquiries  and  the  Mosaic  account  of  the 
creation  of  the  world.  But,  convinced  as  I  am  of 
the  utter  impossibility  that  there  ever  can  be  any 
collision  between  the  purest  piety  and  sound  philo- 
sophy, and  that  these  prejudices  have  been  created 
and  perpetuated  by  authors,  who,  falsely  styling 
themselves  geologists,  have  mixed  up  their  own 
vague  and  erroneous  notions  with  the  history  of  the 
earth  as  given  by  the  inspired  writer,  attempting, 
with  the  presumption  of  ignorance,  to  account  for 
that  which  lies  beyond  the  reach  of  human  investi- 
gation, and  to  explain  it  by  evidence  equally 
misapprehended  and  misapplied,  —  I  would  most 
unequivocally  assert  that  a  just  view  of  the  nature 
and  limits  of  geological  science  warrants  no  such 
reproach.  Abandoning  all  attempts  to  explain  the 
inexplicable,  or  to  reconcile  the  irreconcilable,  it 
confines  itself  to  its  legitimate  purpose  of  accumu- 
lating and  investigating  facts,  of  pointing  out 
analogies,  and  indicating  the  inferences  to  which 
they  lead  ;  "  this  is  far  different  from  that  pre- 


6  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

sumption  which  would  fain  prove  the  truth  of 
Scripture  by  physical  evidence,  or  the  weakness 
that  would  found  a  system  of  natural  philosophy 
on  the  inspired  record."  Nothing  is  more  un- 
warrantable than  attempts  to  identify  theories  in 
science  with  particular  interpretations  of  the  sacred 
text;  and  the  caution  of  Lord  Bacon,  uttered  a 
century  and  a  half  before  geology  even  had  a  name, 
cannot  be  too  often  repeated.  "  Let  no  man,"  said 
he,  "upon  a  weak  conceit  of  sobriety,  or  an  ill- 
applied  moderation,  think  or  maintain  that  a  man 
can  search  too  far,  or  be  too  well  studied  in  the 
book  of  God's  word,  or  the  book  of  God's  works — 
divinity  or  philosophy :  but  rather  let  men  endeavour 
an  endless  progress  or  proficiency  in  both ;  only  let 
them  beware  that  they  apply  both  to  charity  and 
not  to  arrogance — to  use  and  not  to  ostentation  ; 
and  again,  that  they  do  not  unwisely  mingle  or  con- 
found these  learnings  together."  So  deeply  impressed 
have  I  been  with  the  necessity  of  strictly  obeying 
this  admonition,  that  in  all  my  written  or  oral  dis- 
cussions on  geology  I  have,  on  this  subject,  in- 
variably confined  myself  to  a  statement  of  the 
opinions  of  several  eminent  philosophers  and  divines, 
in  the  hope  that  the  example  of  men,  alike  distin- 
guished for  their  piety  and  learning,  cultivating 
with  ardour  this  fascinating  department  of  natural 
science,  and  stating  their  conviction  of  its  high 
importance  and  beneficial  influence  upon  the  mind, 
would  be  a  sufficient  and  direct  reply  to  the  absurd 


§  5.        EXTENT  OP  GEOLOGICAL  PERIODS.         7 

and  unfounded  charges  brought  against  geology. 
On  the  present  occasion,  I  shall  content  myself  with 
the  following  extract  from  the  sermons  of  the 
present  Bishop  of  London  :  "  As  we  are  not  called 
upon  by  Scripture  to  admit,  so  neither  are  we 
required  to  deny  the  supposition,  that  the  matter 
without  form,  and  void,  out  of  ivhich  this  globe  was 
framed,' may  have  consisted  of  the  wrecks  and  relics 
of  more  ancient  worlds,  created  and  destroyed  by 
tJie  same  Almighty  Power  which  called  our  world 
into  being,  and  will  one  day  cause  it  to  pass 
away."* 

Thus,  while  the  Bible  reveals  to  us  the  moral 
history  and  destiny  of  our  race,  and  instructs  us  that 
man  and  the  existing  races  of  living  things  have 
been  placed  but  a  few  thousand  years  upon  the 
earth,  the  physical  monuments  of  our  globe  bear 
witness  to  the  same  truth ;  and  as  astronomy  un- 
folds to  us  innumerable  worlds,  not  spoken  of  in 
the  sacred  record^  geology  in  like  manner  proves, 
not  by  arguments  drawn  from  analogy,  but  by 
incontrovertible  physical  evidence,  that  there  were 
former  conditions  of  our  planet,  separated  from 
each  other  by  vast  intervals  of  time,  during  which 
this  world  was  teeming  with  life,  ere  the  creation  of 
man  and  the  animals  which  are  his  cotemporaries. 

5.  EXTENT  OF  GEOLOGICAL  EPOCHS. — At  the 
first  step  we  take  in  geological  inquiries,  we  are 

*  Sermons,  by  Dr.  Charles  James  Blomfield,  Bishop  of 
London.  8vo.  1829. 


8  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

struck  with  the  immense  periods  of  time  which  the 
phenomena  presented  to  our  view  must  have  required 
for  their  production,  and  the  incessant  changes  which 
appear  to  have  been  going  on  in  the  natural  world  : 
but  we  must  remember  that  time  and  change  are 
great  only  with  reference  to  the  faculties  of  the 
beings  which  note  them.  The  insect  of  a  clay, 
contrasting  its  ephemeral  life  with  that  of  the 
flowers  on  which  it  rests,  would  attribute  an  un- 
changing permanence  to  the  most  evanescent  of 
vegetable  forms ;  while  the  flowers,  the  trees,  and 
the  forests  would  ascribe  an  endless  duration  to  the 
soil  on  which  they  grow:  and  thus,  uninstructed 
man,  comparing  his  transient  earthly  existence 
with  the  solid  framework  of  the  world  he  inhabits, 
deems  the  hills  and  mountains  around  him  coeval 
with  the  globe  itself.  But  with  the  enlargement 
and  cultivation  of  his  mental  powers,  man  takes  a 
more  just,  comprehensive,  and  enlightened  view  of 
the  wonderful  scheme  of  creation;  and  while  in  his 
ignorance  he  imagined  that  the  duration  of  the  globe 
was  to  be  measured  by  his  own  brief  span,  and 
arrogantly  deemed  himself  alone  the  object  of  the 
Almighty's  care,  and  that  all  things  were  created 
for  his  pleasures  and  necessities,  he  now  becomes 
conscious  of  his  own  dependence,  and  entertains  more 
correct  ideas  of  the  mercy,  wisdom,  and  goodness 
of  the  Creator.  And  while  exercising  his  high  pri- 
vilege of  being  alone  capable  of  contemplating  and 
understanding  the  wonders  of  the  natural  world,  he 


§  6,  7.  STRUCTURE  OF  THE  EARTH.  <) 

learns  that  most  important  of  all  lessons — to  doubt 
the  evidence  of  his  senses,  until  confirmed  by  cautious 
and  patient  observation. 

6.  OBJECT  OF  THE  LECTURES. — With  these  in- 
troductory remarks  I  proceed  to  the  consideration 
of  the  subjects  selected  for  the  present  discourse. 
And  here  I  may  observe,  that,  from  the  magnitude 
and  diversity  of  the  objects  embraced  by  geology, 
it  is  scarcely  possible  to  offer,  in  the  space  assigned 
to  a  course  of  popular  lectures,  even  an  epitome 
of   the   wonders    which    modern   researches    have 
brought   to   light.       This    consideration   therefore 
must  be  my   apology   for  the   concise   manner  in 
which  many  interesting  facts  may  perhaps  be  noticed ; 
and  I  would  beg  of  you  to  consider  that  lectures  of 
this  kind  are  intended  to   excite,   rather  than  to 
satisfy,  a  rational  curiosity  ;  that  they  are  designed 
to  promote  a  taste  for  philosophical  pursuits,  but 
cannot  supersede  the  necessity  of  study  and  of  per- 
sonal investigation. 

7.  PHYSICAL  STRUCTURE  OF  THE  EARTH. — 
The  globe  we  inhabit  may  be  described  as  a  planetary 
orb  of  a  few  thousand  miles  in  circumference,  and 
of  a  spheroidal  shape;  its  figure  being  such  as  a 
body  in  a  fluid  state,  and  made  to  rotate  on  its 
axis,  would  assume.     Its  mean  density  is  five  times 
greater  than  that  of  water,  the  interior  being  double 
that  of  the  solid   superficial   crust :    the   internal 
part  of  the  earth,  if  cavernous,  must  therefore  be 
composed  of  very  dense  materials.     Its  surface  is 


10 


THE  WONDERS  OF  GEOLOGY. 


LECT.  I. 


computed  to  contain  190  millions  of  square  miles,  of 
which  three- fifths  are  covered  by  seas,  and  another 
large  proportion  by  vast  bodies  of  fresh  water,  by  polar 
ice  and  eternal  snows;  so  that  taking  into  considera- 
tion sterile  tracts,  morasses.  &c.,  scarcely  more  than 
one-fifth  of  the  surface  of  the  globe  is  fit  for  the 
habitation  of  man  and  terrestrial  animals.*  The  area 
of  the  Pacific  Ocean  alone,  is  estimated  as  equal  to 
the  entire  surface  of  the  dry  land.  The  distribution 
of  the  land  is  exceedingly  irregular,  the  greater  pro- 
portion being  situated  in  the  northern  hemisphere, 


TAB.  1.  —  THE  EARTH  AS  SEEN  FROM  THE 


as  a  reference  to  a  terrestrial  globe,  or  a  map  of  the 
world,  will  clearly  demonstrate. 

*  Bakewell's  Geology.  f  DC  la  Beche. 


§8.  DISTRIBUTION  OF  ANIMALS.  11 

In  a  geological  point  of  view,  dry  land  may  be 
considered  as  so  much  of  the  crust  of  the  earth  as  is 
now  above  the  level  of  the  water,  beneath  which 
it  may  again  disappear.  From  accurate  calculations 
it  is  proved  that  the  present  land  might  be  distri- 
buted over  the  bed  of  the  ocean,  in  such  manner 
that  the  surface  of  the  globe  would  present  an  un- 
interrupted sheet  of  water.  Thus  we  perceive  that 
every  imaginable  distribution  of  land  and  water  may 
take  place ;  and  consequently  that  every  variety  of 
organic  life  may  find  at  different  periods  suitable 
abodes. 

8.  GEOGRAPHICAL  DISTRIBUTION  OF  ANIMALS. 
—The  investigation  of  the  laws  which  govern  the 
geographical  distribution  of  animals  and  vegetables 
is  highly  interesting ;  but  as  my  limits  compel  me 
to  be  brief,  I  must  refer  you  to  the  third  volume  of 
Mr.  Lyell's  "  Principles  of  Geology,"  for  more  ample 
details.  It  will  be  sufficient  for  our  present  purpose 
to  state,  that  although  it  might  have  been  expected 
that,  all  other  circumstances  being  equal,  the  same 
animals  and  plants  would  have  been  found  in  places 
of  like  climate  and  temperature,  this  identity  of  dis- 
tribution does  not  exist.  When  America  was  first 
discovered,  the  indigenous  quadrupeds  were  all  dis- 
similar to  those  of  the  old  world.  The  elephant, 
rhinoceros,  hippopotamus,  giraffe,  camel,  horse, 
buffalo,  lion,  tiger,  &c.  were  not  met  with  on  the 
new  continent;  while  the  American  species  of  mam- 
malia, as  the  llama,  jaguar,  paca,  coati,  sloth,  &c. 


12  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

were  unknown  in  the  olu.  New  Holland  contains, 
as  is  well  known,  a  most  singular  assemblage  of 
mammalia,  consisting  of  more  than  forty  species 
of  marsupial  animals,  of  which  the  kangaroo  is  a 
familiar  example.  The  islands  of  the  Pacific  Ocean 
possess  no  quadrupeds,  except  hogs,  dogs,  rats,  and 
a  few  bats. 

The  distribution  of  vegetable  life,  although  per- 
haps more  arbitrarily  fixed  by  temperature  and  by 
local  influences  than  that  of  animals,  presents  many 
anomalies.  From  numerous  observations,  however, 
it  appears  that  vegetable  creation  took  place  in 
different  centres,  each  having  been  the  focus  of  a 
peculiar  genus  or  species ;  for  many  plants  have  a 
local  existence,  and  vegetate  naturally  in  one  district 
alone ;  thus  the  cedar  of  Lebanon  is  indigenous  on 
that  mountain,  and  does  not  grow  spontaneously  in 
any  other  part  of  the  world.  It  is  also  ascertained 
that  certain  great  divisions  of  the  vegetable  kingdom 
are  distributed  over  certain  regions  :  we  shall  have 
occasion  to  refer  to  this  subject  in  the  lecture  de- 
voted to  the  consideration  of  Fossil  Botany. 

9.  TEMPERATURE  OF  THE  EARTH. — The  tem- 
perature of  the  surface  of  the  globe  depends  on 
the  action  of  solar  light  and  heat  ;  hence  the 
difference  of  the  seasons,  and  climates  of  various 
latitudes ;  but  there  are  many  causes  which  modify 
the  distribution  of  the  sun's  influence,  and  produce 
great  local  variations :  under  equal  circumstances, 
however,  the  temperature  is  found  progressively  to 


§  10.  TEMPERATURE  OF  THE  EARTH.  13 

diminish  from  the  equator  to  the  poles.  There  is 
also  an  internal  source  of  heat,  the  cause  of  which 
has  not  yet  been  determined,  but  is  probably  con- 
nected with  the  original  constitution  of  our  planet. 
It  has  been  ascertained,  by  careful  experiments,  that 
below  the  depth  to  which  the  solar  heat  can  pene- 
trate, there  is  an  invariable  increase  of  temperature, 
amounting  to  1°  of  Fahrenheit  for  every  fifteen 
yards  :  so  that  it  is  possible  that  at  the  depth  of  100 
miles  beneath  the  surface  of  the  earth,  even  the 
least  fusible  mineral  masses  may  be  in  a  state  of 
incandescence. 

10.  NATURE  OF  THE  CRUST  OF  THE  GLOBE. — 
The  greatest  thickness  of  the  superficial  crust  of  the 
globe,  that  is,  of  the  mass  of  solid  materials  which 
the  ingenuity  of  man  has  been  able  to  examine, 
from  the  highest  mountain  peaks  to  the  greatest 
natural  or  artificial  depths,  is  estimated  at  about 
ten  miles.  As  the  earth  is  nearly  eight  thousand 
miles  in  diameter,  the  entire  series  of  strata  hitherto 
explored  is,  therefore,  but  very  insignificant  com- 
pared with  the  magnitude  of  the  globe  ;  bearing 
about  the  same  relative  proportion,  as  the  thick- 
ness of  this  paper,  to  an  artificial  sphere  a  foot 
in  diameter ;  the  inequalities  and  crevices  in  -the 
varnish  of  such  an  instrument  would  be  equal 
in  proportionate  size  to  the  highest  mountains 
and  deepest  valleys.  In  the  following  diagram,* 

•  From  the  Penny  Cyclopaedia. 


14 


THE  WONDERS  OF  GEOLOGY. 


LECT  I. 


the  relative  proportions  of  the  crust  of  the  earth, 
and  the  inequalities  of  its  surface,  as  compared 
with  the  mass  of  our  planet,  are  attempted  to  be 
shown.* 


TAB.  2.— DIAGRAM  TO  ILLUSTRATE  THE  PROPORTIONATE  THICKNESS 
OF  THE  CRUST  OF  THE  EARTH. 

The  line  from  e  to  k  represents  a  depth  of  500 
miles  ;  to  the  point  i,  a  depth  of  100  miles  ;  to  the 
line  /,  forty-five  miles  above  the  surface,  the  sup- 
posed limit  of  the  earth's  atmosphere ;  and  the  dark 
line,  a  thickness  of  ten  miles,  the  estimated  depth 
of  the  crust  of  the  earth.  The  points  d,  e,  /,  <?, 
indicate  the  altitude  of  the  highest  mountains  in  the 
world ;  •]*  the  depth  of  the  sea  is  shown  by  the  line 

*  To  preserve  as  far  as  possible  the  language  and  spirit  of 
the  original  lectures,  the  references  to  the  diagrams  and  speci- 
mens are  retained.  The  Author's  collection  is  now  removed 
from  Brighton,  and  deposited  in  the  British  Museum. 

f  The  highest  peak  of  the  Alps,  and  of  Europe,  is  Mont 
Blanc,  which  is  15,660  feet  above  the  level  of  the  sea — of  the 
Andes,  Chimborazo,  which  is  21,425  feet — and  of  the  Hima- 
layas, Dhwalagiri,  estimated  at  28,000  feet,  being  more  than 
five  miles  of  perpendicular  altitude. 


§10.          THE  CRUST  OF  THE  GLOBE.  ]j 

a,  h,  at  the  extremities  of  the  arc.  As  a  thickness 
of  100  miles  so  far  exceeds  that  of  the  whole  of  the 
strata  that  are  accessible  to  human  observation,  we 
cannot  doubt  that  disturbance  of  the  earth's  sur- 
face, even  to  ten  times  the  depth  of  those  which 
come  within  the  scope  of  geological  inquiry,  may 
take  place,  without  in  any  sensible  degree  affecting 
the  entire  mass  of  the  globe,*  If  these  facts  be 
duly  considered,  the  mind  will  be  prepared  to  receive 
one  of  the  most  startling  propositions  in  modern 
geology — namely,  that  the  highest  mountains  have 
once  been  the  bed  of  the  sea,  and  have  been  raised 
to  their  present  situations  by  subterranean  agency, — 
some  slowly,  others  suddenly,  but  all,  geologically 
speaking,  at  a  comparatively  recent  period. 


*  Mr.  Fairholme  suggests  the  following  ingenious  method 
to  convey  a  general  idea  of  the  relative  magnitude  of  the  in- 
equalities of  the  earth's  surface.  If  we  form  a  scale  on  the  sand 
of  the  sea-shore  in  the  proportion  of  an  inch  to  a  mile,  we  shall 
have  a  circle  of  8000  inches,  or  222  yards  in  diameter,  which, 
when  marked  out  with  small  stakes,  appears  a  very  large  area. 
Placing  ourselves  upon  any  part  of  this  circumference,  we  have 
an  opportunity  of  taking  a  jus{,  though  microscopic,  view  of  the 
surface.  The  highest  mountains  in  the  world  would  be  repre- 
sented by  a  little  ridge  five  inches  high ;  the  profound  abyss  of 
the  ocean  by  a  groove  of  the  same  depth ;  while  the  medium 
inequality  of  sea  and  land  would  not  exceed  one  inch.  To  form 
an  idea  of  smaller  objects,  we  must  examine  an  inch  scale, 
finely  graduated,  by  the  aid  of  a  microscope,  and  we  shall  then 
find  that  the  tallest  man  would  be  about  the  880th  part  of  an 
inch  in  height — the  size  of  the  smallest  animalcule  observed  in 
fluids. 


16  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

11.  COMPOSITION  OF  THE  ROCKS  AND  STRATA. 
— The  superficial  crust  of  the  globe  is  composed  of 
numerous  layers  and  masses  of  earthy  substances, 
of  which  combinations  of  iron,  lime,  and  silex,  or 
flint,  constitute  a  large  proportion  ;  the  latter  form- 
ing forty-five  per  cent,  of  the  whole.     Those  strata 
which  have  been  deposited  the  latest,  bear  evident 
marks  of  mechanical  origin,  and  are  the  water-worn 
ruins  of  older  rocks  ;  as  we  descend,  materials  of  a 
denser  character  appear,  which  also  exhibit  proofs 
of  having  been  subject  to  the  action  of  water ;  but 
when  we  arrive  at  the  lowermost  in  the  scale,   a 
crystalline  structure  generally  prevails ;   and  while 
in  the  newer  strata,  trees,  plants,  shells,  and  other 
remains  of  animals   and  vegetables  are  found  in 
profusion,  in  the  most  ancient  rocks  all  traces  of 
organic  forms  are  absent. 

12.  CLASSIFICATION  OF  ROCKS. — In  the  infancy 
of  the  science  these  remarkable  facts  gave  rise  to 
an  ingenious  theory,  which,  however,  from  being 
founded  on  insufficient  data,  has  proved  untenable. 
Still  it  may  be  convenient  to  notice  the  hypothesis, 
since  the  terms  employed  are  still  retained  in  the 
nomenclature    of    geology.       Agreeably    to    this 
theory,  the  mineral  masses  of  which  the  crust  of 
the   earth  is  composed,    are  separated   into   three 
groups. 

13.  PRIMARY  ROCKS. — 1st.  The  Primitive  (now 
called  Primary)  Rocks ;    such  as  granite,  sienite, 
porphyry,  &c. :  these  are  of  a  crystalline  structure, 


§14,15.  CLASSIFICATION  OF  STRATA.  17 

and  have  evidently  been  reduced  to  their  present 
state  by  igneous  agency.  They  are  the  lowermost 
rocks,  and  constitute  the  foundation,  on  which  all 
the  newer  strata  have  been  deposited  ;  they  also 
attain  the  highest  elevations  on  the  surface  of  the 
globe.  They  were  termed  primitive,  because  it 
was  inferred,  from  the  entire  absence  of  organic 
remains,  that  they  had  been  formed  before  the  crea- 
tion of  animals  and  vegetables ;  but  it  is  now  ascer- 
tained that  granite  and  its  associated  rocks  are  of 
various  ages,  and  are  sedimentary  deposits  altered 
by  exposure  to  a  very  high  temperature. 

14-.  TRANSITION  STRATA. — 2d.  The  Transition 
Strata.  These  are  super-imposed  on  the  primitive, 
are  more  or  less  distinctly  stratified,  and  contain 
the  fossilized  remains  of  animals  and  plants.  They 
received  the  name  of  transition,  because  it  was 
assumed  that  they  had  been  formed  at  a  period 
when  the  surface  of  the  earth  and  the  seas  were 
passing  into  a  state  fit  for  the  reception  of  orga- 
nized beings.  Modern  researches  have,  however, 
shown  that  they  are,  like  the  primary  rocks,  strata 
modified  by  the  effects  of  heat  under  great  pres- 
sure. 

15.  SECONDARY  STRATA. — 3d.  The  Secondary. 
These  have  clearly  originated  from  the  destruction 
of  the  more  ancient  rocks,  and  have  been  deposited 
in  hollows  or  depressions,  by  the  action  of  rivers 
and  seas.  They  abound  in  the  mineralized  remains 
of  animals  and  plants ;  the  most  ancient  inclosing 
c 


18  THE  WONDERS  OF  GEOLOGY.  LECT,  I 

zoophytes  and  shells  r  the  next  in  antiquity  conr 
taining,  in  addition,  vegetable  remains  and  fishes ; 
those  which  succeed  enveloping  not  only  fishes, 
shells,  zoophytes,  and  plants,  but  also  insects  and 
bones  of  enormous  reptiles,  of  birds,  and  of  one  or 
more  genera  of  marsupial  animals.  The  chalk  is 
the  uppermost,  or  most  recent  of  this  class.  As 
the  secondary  rocks  have  manifestly  been  formed 
by  the  agency  of  water,  it  is  clear  that  they  were 
originally  deposited  in  horizontal,  or  nearly  hori- 
zontal layers  or  strata,  although  by  far  the  greater 
portion  has  since  been  broken  up,  and  now  lies  in 
directions  more  or  less  inclined  to  the  horizon, 

For  the  convenience  of  study,  this  subdivision  of 
the  rocks  is  still  retained,  as  will  hereafter  be  shown. 
To  the  above  groups  modern  geologists  have  added 
a  fourth  class,  the  Tertiary. 

16.  TERTIARY   STRATA. — 4th.    The  Tertiary.* 
These  lie  in  hollows  or  basins  of  the  chalk,  and 
other  secondary  rocks,  and  are  formed  of  the  de- 
tritus of  the  more  ancient  beds.     They  abound  in 
shells,  plants,  zoophytes,  Crustacea,  fishes,  &c. :  and 
in  them,  with  but  one  exception,  the  bones  of  mam- 
malia first  appear. 

17.  ALLUVIAL  DEPOSITS. — Of  a  later  formation 
than  the  tertiary  strata,  are  those  accumulations  of 
water-worn  materials,  which  are  spread  over  the 
surface  of  almost  every  country  more  or  less  abun- 

*  See  Plate  X.  Fig.  3. 


§  18.  GEOLOGICAL  MUTATIONS.  19 

dantly.  These  are  termed  alluvial  deposits;*  they 
contain  remains  of  the  existing  races  of  animals  and 
plants,  associated  with  those  of  species  that  are  no 
longer  to  be  met  with  on  the  face  of  the  earth. 

Even  this  slight  examination  of  the  strata  affords 
convincing  proofs  of  a  former  condition  of  animated 
nature,  widely  different  from  the  present.  We  have 
evidence  of  a  succession  of  periods  of  unknown 
duration,  in  which  both  the  land  and  the  sea  teemed 
with  forms  of  existence  that  have  successively  dis- 
appeared and  given  place  to  others ;  and  these  again 
to  new  races,  approaching  gradually  more  and  more 
nearly  to  those  which  now  inhabit  the  earth,  till  at 
length  existing  species  make  their  appearance. 
.  18,  GEOLOGICAL  MUTATIONS. — From  this  view 
of  the  physical  structure  of  our  planet  we  learn,  at 
least  so  far  as  the  limited  powers  of  man  can  pene- 
trate into  the  history  of  the  past,  that  the  distribution 
of  land  and  water  on  its  surface  has.  been  under- 
going perpetual  mutation  ;  yet,  that  through  a  vast 
period  of  time,  the  physical  condition  of  the  earth 
has  not  materially  differed  from  the  present ;  that 
the  dry  land  has  been  clothed  with  vegetation,  and 
tenanted  by  appropriate  inhabitants ;  and  that  the 
sea  and  the  bodies  of  fresh  water  have  swarmed 
with  living  forms ;  that  at  a  remote  epoch,  though 
animal  and  vegetable  life  existed,  the  species  were 

»  The  term  diluvial  is  applied  by  some  geologists  to  the  most 
ancient  of  these  deposits  ;  and  that  of  alluvial  to  the  modern 
accumulations  only. 

c2 


20  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

wholly  different  from  any  that  now  abound,  and  the 
greater  number  of  a  nature  fitted  to  live  in  a  tem- 
perature much  higher,  and  more  equally  distributed, 
than  occurs  in  the  present  state  of  the  earth  ;  and 
lastly,  that  in  the  inferior,  or  most  ancient  beds,  all 
traces  of  mechanical  action,  and  of  animal  and  vege- 
table organization,  are  absent ;  or  in  other  words, 
have  either  never  existed,  or  have  been  altogether 
obliterated.  Before  entering  upon  that  department 
of  the  subject  to  which  the  term  Geology  is  com- 
monly restricted,  it  will  facilitate  our  comprehension 
of  many  of  the  appearances  which  the  strata  pre- 
sent to  our  notice,  if  in  this  place  we  endeavour 
to  penetrate  the  mystery  that  veils  the  earliest 
condition  of  the  earth  ;  but  this  we  shall  in 
vain  attempt,  if  we  restrict  our  examination  to 
the  physical  phenomena  observable  in  our  own 
planet. 

19.  CONNEXION  OF  GEOLOGY  WITH  ASTRONOMY. 
— Here  Geology  leads  to  Astronomy,  and  teaches 
us  to  look  to  the  kindred  spheres  around  us  for  the 
elucidation  of  the  early  history  of  the  globe ;  and 
to  consider  the  earth  but  as  an  attendant  satellite 
on  a  vast  central  luminary.  The  solar  system  con- 
sists of  the  sun,  whose  mass  is  made  up  of  solid 
matter,  which  is  surrounded  by  a  luminous  atmo- 
sphere, or  nebulosity ;  and  of  eleven  small  planets, 
which  revolve  around  it  in  various  periods ;  the 
earth  being  the  third  in  distance  from  the  sun,  and 
in  bulk,  as  compared  with  that  body,  of  the  size  of 


J  19.  STRUCTURE  OF  THE  MOON.  21 

a  pea  to  that  of  a  globe  two  feet  in  diameter  :  and 
having  a  satellite,  the  moon,  revolving  round  it. 


TAB.  3.— TELESCOPIC  VIEW  OF  THE  MOON. 

Upon  examining  the  moon  with  powerful  tele- 
scopes, we  perceive  that  its  surface  is  diversified  by 
hills  and  valleys ;  that  it  is  a  congeries  of  moun- 
tains, many  of  which  are  manifestly  volcanic,  the 
lava  currents  being  distinctly  visible.  We  see  in 
fact  a  torn,  crateriform,  and  disturbed  surface,  like 
that  which  we  may  conceive  would  be  presented  by 
our  earth,  were  the  pinnacles  of  the  granite  moun- 
tains unabraded,  and  the  valleys  neither  smoothed, 
nor  filled  up  by  sedimentary  deposits.*  In  Venus 
*  See  Appendix  A. 


22  THE  WONDERS  OF  GEOLOGY.  LECT.  L 

and  Mercury  the  mountains  appear  to  be  enormous; 
while  in  Jupiter  and  Saturn  there  are  but  slight 
traces  of  any  considerable  elevations. 

20.  NEBULAR  THEORY  OF  THE  UNIVERSE. — 
Astronomy  instructs  us  that  in  the  original  con- 
dition of  the  solar  system  the  sun  was  the  nucleus 
of  a  nebulosity,  or  luminous  mass,  which  revolved 
on  its  axis,  and  extended  far  beyond  the  orbits  of  all 
the  planets  ;  the  planets  as  yet  having  no  existence. 
Its  temperature  gradually  diminished,  and  becoming 
contracted  by  cooling,  the  rotation  increased  in 
rapidity,  and  zones  of  nebulosity  were  successively 
thrown  off,  in  consequence  of  the  centrifugal  force 
overpowering  the  central  attraction  :  the  condensa- 
tion of  these  separated  masses  constituted  the  planets 
and  satellites.  But  this  view  of  the  conversion  of 
gaseous  matter  into  planetary  bodies  is  not  limited 
to  our  own  system ;  it  extends  to  the  formation  of 
the  innumerable  suns  and  worlds  which  are  dis- 
tributed throughout  the  universe.  The  sublime 
discoveries  of  modern  astronomers  have  shown  that 
«very  part  of  the  realms  of  space  abounds  in  large 
expansions  of  attenuated  matter,  termed  nebulce, 
which  are  irregularly  reflective  of  light,  of  various 
figures,  and  in  different  states  of  condensation, 
from  that  of  a  diffused  luminous  mass,  to  suns  and 
•planets  like  our  own.  It  must  be  admitted  that 
this  assertion  appears  astounding, — and  that  it  may 
fairly  be  asked  if  man,  the  ephemeron  of  the  mate- 
rial world,  can  measure  the  vast  epochs  which 


§  20.  NEBUtAR  THEORY  OF  THE  UNIVERSE.  2;> 

mark  the  progressive  development  of  suns  and 
systems  ?  The  genius  of  Herschel  has  effected 
this  wonderful  achievement,  and  explained  the  suc- 
cessive changes  by  which  suns  and  worlds  are 
formed,  through  the  agency  of  the  eternal  and 
unerring  laws  of  the  Almighty.  By  laborious  and 
unremitting  observations,  that  illustrious  philoso- 
pher, and  his  highly  gifted  son,  have  demonstrated 
the  progress  of  nebular  condensation, — not  indeed 
from  the  appearances  presented  by  a  single  nebula, 
(for  the  process,  probably,  can  only  become  sensible 
through  the  lapse  of  hundreds,  or  thousands,  of 
years,)  but  by  observations  on  the  almost  endless 
series  of  related,  contemporaneous  objects  in  every 
varied  state  of  progression,  from  that  of  a  cloud  of 
luminous  vapour,  to  the  most  dense  and  mighty  orbs 
that  appear  in  the  firmament.  As  the  naturalist  in 
the  midst  of  a  forest  is  unable  by  a  glance  to  dis- 
cover that  the  trees  around  him  are  in  a  state  of 
progressive  change ;  yet  perceiving  that  there  are 
plants  in  different  stages  of  growth,  from  the  acorn 
just  bursting  from  the  soil  to  the  lofty  oak  that 
stands  the  monarch  of  the  woods,  can  readily,  from 
the  succession  of  changes  thus  at  once  presented 
to  his  view,  ascertain  the  progression  of  vegetable 
life,  although  extending  over  a  period  far  beyond 
his  own  brief  existence  : — in  like  manner,  the  astro- 
nomer, by  surveying  the  varied  condition  of  the 
heavenly  bodies  around  him,  can,  by  careful  induc- 
tion, determine  the  nature  of  those  changes,  which, 


24  THE  WONDERS  OF  GEOLOGY.  Lzci.  I. 

as  regards  a  single  nebrla,  the  human  mind  might 
otherwise  be  unable  to  ascertain.*  Thus  Herschel 
has  traced  from  nebular  masses  of  absolute  vague- 
ness, to  others  which  present  form  and  structure, 
the  effects  of  the  mysterious  law  which  governs  the 
stupendous  stellular  phenomena  that  are  constantly 
taking  place. 

21.  DIFFERENT  STATES  OF  NEBULJE. — Some  of 


Tab.  4. — TELESCOPIC  APPEARANCE  OF  VARIOUS  NEBULAE. 

the  nebulce   appear  as  mere  clouds  of  attenuated 
light — others  as  if  curdling  into  separate  masses — 

*  Sir  John  Herschel  states,  that  the  only  change  in  a  nebula 
which  he  has  yet  observed,  is  in  that  of  Orion.  A  small  trans- 
verse strip,  which  when  he  first  figured  that  nebula  was  straight, 
had  become  curved,  and  showed  a  knotty  appearance,  which  it 
did  not  before  possess. — Athenaum^  No.  565,  p.  596. 


§  21.  DIFFERENT  STATES  OF  NEBULA.  25 

while  many  seem  assuming  a  spheroidal  figure. 
Others  again  present  a  dense  central  nucleus  of 
light  surrounded  by  a  luminous  halo ;  and  a  series 
may  thus  be  traced,  from  clusters  of  round  bodies 
with  one  or  more  increased  points  of  condensation, 
or  of  central  illumination,  to  separate  nebulae  with 
single  nulcei,  and  with  rings,  to  a  central  disk  con- 
stituting a  nebular  star — and  finally  to  an  orb  of 
light  with  a  halo  like  the  sun  ! 

In  the  comets,  those  nebular  bodies  which  belong 
to  our  own  and  other  systems,  we  have  evidence 
that  even  in  the  most  diffused  state  of  the  luminous 


Tab.  5. — TELESCOPIC  VIEW  OF  ENCKE'S  COMET. 

matter,  the  masses  which  it  forms  are  subservient 
to  the  laws  of  orbicular  motion :    of  this  fact  an 


2ft  THE  WONDERS  OF  GEOLOGY.  LECT.'I. 

interesting  proof  is  afforded  by  Encke's  comet,  that 
mere  wisp  of  vapour,  which  in  a  period  but  little 
exceeding  three  years,  revolves  around  the  central 
luminary  of  our  system. 

This  beautiful  theory  of  Herschel,  and  La  Place, 
explains  by  an  easy  and  evident  process  the  forma- 
tion of  planets  and  satellites,  and  accounts  for  the 
uniform  direction  of  their  revolutions.  And  not 
only  is  it  believed  that  such  is  the  law  which 
the  Creator  has  established  for  the  maintenance 
and  government  of  the  universe,  but  it  is  satis- 
factorily shown,  upon  mechanical  principles,  that 
such  nebulae  must  of  necessity  produce  planetary 
bodies. 

22.  FORMATION  OF  THE  SOLAR  SYSTEM. — In 
our  own  system,  the  sun  is  a  planetary  orb  with 
a  luminous  atmosphere,  the  central  nucleus  of  a 
once  extensive  nebulosity.  During  the  conden- 
sation of  this  nebula  the  planets  \vere  successively 
thrown  off;  the  most  distant,  as  Herschel,  being  the 
first  or  most  ancient,  followed  by  Saturn,  Jupiter, 
the  four  asteroids,  Mars,  the  Earth,  Venus,  and 
Mercury;  the  satellites,  as  distinct  worlds,  being 
the  most  recent  of  the  whole.  It  is  inferred,  that 
in  any  given  state  of  the  rotating  solar  mass,  the 
outer  portion  or  ring  might  have  its  centrifugal 
force  exactly  balanced  by  gravity;  but  increased 
rotation  would  throw  off  that  ring,  which  might 
sometimes  retain  its  figure,  of  which  we  have  a 
beautiful  example,  in  Saturn.  This  result,  however, 


§  22.  FORMATION  OF  THE  SOLAR  SYSTEM.  27 

could  not  take  place  unless  the  annular  band  were 
of  uniform  composition,  which  would  rarely  be  the 


Tab.  6. — TELESCOPIC  VIEW  OP  SATURN. 

case ;  hence  the  ring  would  most  generally  divide 
into  several  portions,  which  might  sometimes  be  of 
nearly  equal  bulk,  as  in  the  asteroids;  while  in 
others  they  might  coalesce  into  one  mass.  The 
solar  nebulae,  thus  separated  at  various  periods,  and 
constituting  planets  in  a  gaseous  state,  would  neces- 
sarily have  a  rotatory  motion,  and  revolve  in  varying 
orbits  around  the  central  nucleus ;  and  as  refrige- 
ration and  consolidation  proceeded,  each  might 
project  entire  annuli  or  rings,  and  satellites,  in  like 
manner  as  the  sun  had  thrown  off  the  planets  them* 
selves. 

In  addition  to  the  appearances  presented  by  the 
nebulae   of  various   states   of  attenuation   and  of 


28  .          THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

solidity,  we  have  in  the  orbs  of  our  own  system 
evidence  of  corresponding  gradations  of  density* 
The  planets  near  to  the  sun  are  denser  than  those 
which  are  more  distant :  thus  Mercury,  which  is  the 
nearest,  is  the  heaviest,  being  almost  thrice  as  dense 
as  the  earth ;  while  the  density  of  Jupiter,  which  is 
far  removed,  is  not  more  than  one-third  that  of  our 
planet;  and  Saturn,  which,  with  the  exception  of 
Herschel,  is  the  remotest,  is  but  little  more  than 
one-eighth  as  dense  ;  and  is  supposed  to  be  as  light 
as  cork.* 

But  I  must  not  pursue  this  sublime  subject  far- 
ther; those  who  feel  desirous  of  more  ample  in- 
formation may  consult  a  popular  abstract  of  the 
discoveries  of  modern  astronomy,  recently  published, 
under  the  title  of  "  Views  of  the  Architecture  of  the 
Heavens."  f 

You  will  at  once  perceive  that  this  theory  can  in 
no  wise  affect  the  inference  that  the  universe  is  the 
work  of  an  all-wise  and  omnipotent  Creator.  "Let 
it  be  assumed  that  the  point  to  which  this  hypothesis 
guides  us,  is  the  ultimate  boundary  of  physical 
science — that  the  nearest  glimpse  we  can  attain  of 
the  material  universe,  displays  it  to  us  as  occupied 
by  a  boundless  abyss  of  attenuated  matter  ;  still  we 
are  left  to  inquire  how  space  became  thus  occupied 
•' — whence  originated  matter  thus  luminous  ?  And 

*  Introduction  to  Astronomy,  by  Sir  J.  F.  W.  Herschel. 
f  By  Dr.  Nichol,  Professor  of  Practical  Astronomy  in  the 
University  of  Glasgow. 


§  23.  GASEOUS  STATE  OF  THE  EARTH.  29 

if  we  are  able  to  establish  by  physical  proofs,  that 
the  first  fact  which  the  human  mind  can  trace  in  the 
history  of  the  heavens  is,  that  *  there  was  light,  we 
are  irresistibly  led  to  the  conclusion,  that  ere  this 
could  take  place,  «  GOD  SAID,  Let  there  be  light.'  "  * 

This  theory  of  the  condensation  of  nebular  matter 
into  suns  and  worlds,  marvellous  as  it  may  appear, 
will  be  found  on  due  reflection  to  offer  the  only 
rational  explanation  of  the  phenomena  observable 
in  the  sidereal  heavens,  and  in  our  own  globe  ;  and 
its  beautiful  simplicity  is  in  correspondence  with  the 
unity  of  design  so  manifest  throughout  the  works  of 
the  Eternal. 

23.  GASEOUS  STATE  OF  THE  EARTH. — Though 
an  unscientific  inquirer  may  find  it  difficult  to  com- 
prehend that  our  planet  once  existed  in  a  gaseous 
state,  this  difficulty  will  vanish  upon  considering  the 
nature  of  the  changes  that  all  the  materials  of 
which  the  earth  is  composed  must  constantly  un- 
dergo. Water  offers  a  familiar  example  of  a  sub- 
stance existing  on  the  surface  of  the  globe,  in  the 
separate  states  of  rock,  fluid,  and  vapour;  for 
water  consolidated  into  ice  is  as  much  a  rock  as 
granite  or  the  adamant,  and,  as  we  shall  hereafter 
have  occasion  to  remark,  has  the  power  of  pre- 
serving for  an  indefinite  period  the  animals  and 
vegetables  that  may  be  therein  imbedded.  Yet, 
upon  an  increase  of  temperature,  the  glaciers  of 

*  Professor  WhewelL 


30  xHE  WONDERS  OF  GEOLOGY.  LECT.  I. 

the  Alps,  and  the  icy  pi  inacles  of  the  Arctic  cir- 
cles, disappear ;  and,  by  a  degree  of  heat  still 
higher,  would  be  resolved  into  vapour;  and  by  other 
agencies  might  be  separated  into  two  invisible 
gases — oxygen  and  hydrogen.  Metals  may  in  like 
manner  be  converted  into  gases  ;  and  in  the  labo- 
ratory of  the  chemist,  all  kinds  of  matter  easily  pass 
through  every  grade  of  transmutation,  from  the 
most  dense  arid  compact  to  an  aeriform  state.  We 
cannot,  therefore,  refuse  our  assent  to  the  conclu- 
sion, that  the  entire  mass  of  our  globe  might  be 
resolved  into  a  permanently  gaseous  form,  merely 
by  the  dissolution  of  the  existing  combinations  of 
matter. 

24-.  GEOLOGY  ILLUSTRATED  BY  ASTRONOMY. — 
From  the  light  thus  shed  by  modern  Astronomy 
upon  many  of  the  dark  and  mysterious  pages  of  the 
earth's  physical  history,  we  learn  that  the  dynamical 
changes  which  have  taken  place  in  our  globe — all 
the  wonderful  transmutations  of  its  crust  revealed 
to  us  by  geological  investigations — may  be  referable 
to  the  operation  of  the  one,  simple,  and  universal 
law,  by  which  the  condensation  of  nebular  masses 
into  worlds,  through  periods  of  time  so  immense  as 
to  be  beyond  the  power  of  human  comprehension, 
is  governed. 

The  internal  heat  of  the  globe— the  evidence 
afforded  by  fossil  organic  remains  of  a  higher  and 
more  equally  diffused  temperature  of  the  surface  in 
an  earlier  state  of  the  earth — and  the  elevations 


$25.  METEORITES.  31 

and  dislocations  of  its  crust  which  have  taken  place, 
and  are  still  going  on — all  refer  to  such  an  origin, 
and  to  such  a  constitution  of  our  planet,  as  that 
contemplated  by  the  nebular  theory.  The  elevatory 
process  is  not  peculiar  to  the  earth ;  for,  as  we  have 
elsewhere  remarked,  Venus,  Mercury,  the  Moon, 
and  perhaps  the  Sun  itself,  exhibit  evidence  of  a 
similar  action.*  In  a  philosophical  point  of  view, 
the  present  physical  epoch  of  the  earth  '<  is  that  of 
the  fluidity  of  water,  which  is  the  nebulous  bed  or 
stratum  last  condensed,  and  which  exerts  mecha- 
nical and  chemical  action  upon  the  previously  con- 
solidated materials."  f 

25.  METEORITES.  —  Intimately  connected  with 
this  division  of  our  subject,  is  the  remarkable  fact 
of  the  fall  of  foreign  bodies,  called  meteorites,  or 
meteoric  stones,  on  our  earth.  The  specimen  before 
me,  for  which  I  am  indebted  to  my  kind  and  distin- 
guished friend,  Professor  Silliman,  of  Yale  College, 
Newhaven,  Connecticut,  is  a  fragment  of  the  mass 
which  fell  at  Nanjenoy,  in  Maryland,  in  North 
America,  a  few  years  since.  The  following  descrip- 
tion by  an  eye-witness  of  its  descent,  will  serve  to 
illustrate  the  ordinary  phenomena  which  attend  the 
appearance  of  these  mysterious  visitors.  J 

"  On  the  10th  of  February,  between  the  hours  of 


*  This  subject  is   treated  at  large  in  Mr.  De  la  Beche's 
"  Researches  in  Theoretical  Geology." 
t  Dr.  Nichol. 
1  American  Journal  of  Science. 


32  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

twelve  and  one  o'clock,  I  heard  an  explosion,  as  I 
supposed  of  a  cannon,  but  somewhat  sharper.  I  im- 
mediately advanced  with  a  quick  step  about  twenty 
paces,  when  my  attention  was  arrested  by  a  buzzing 
noise,  as  if  something  was  rushing  over  my  head, 
and  in  a  few  seconds  I  heard  something  fall.  The 
time  which  elapsed  from  my  first  hearing  the  report 
to  the  falling,  might  have  been  fifteen  seconds.  I 
then  went  with  some  of  my  servants  to  ascertain 
where  it  had  fallen,  but  did  not  at  first  succeed  ; 
however,  in  a  short  time  the  place  was  found  by 
my  cook,  who  dug  down  to  the  stone,  which  was 
discovered  about  two  feet  below  the  surface.  It  was 
sensibly  warm,  and  had  a  sulphurous  smell :  was  of 
an  oblong  shape,  and  weighed  sixteen  pounds  and 
seven  ounces.  It  has  a  hard  vitreous  surface.  I 
have  conversed  with  many  persons,  living  over  an 
extent  of  perhaps  fifty  miles  square  :  some  heard 
the  explosion,  while  others  noticed  only  the  subse- 
quent whizzing  noise  in  the  air ;  all  agree  in  stating 
that  the  sound  appeared  directly  over  their  heads. 
The  day  was  perfectly  fine  and  clear.  There  was 
but  one  report  heard,  and  but  one  stone  fell,  to  my 
knowledge  ;  there  was  no  peculiar  smell  in  the  air  : 
it  fell  within  250  yards  of  my  house."* 

**  An  analysis  of  this  meteorite  gave  the  following  results : — 
Oxide  of  Iron  .     .     .     .24. 

Nickel    .     .     .     1.25 

Silica  with  earthy  matter    3.46 
Sulphur,  a  trace. 

28JV 


§  26.                                        METEORITES.  33 

26.    MRS.  SOMERVILLE    ON   METEORITES. That 

ornament  and  pride  of  her  sex,  Mrs.  Somerville,  has 
the  following  interesting  remarks  on  this  subject : — 
"  So  numerous  are  the  objects  which  meet  our  view 
in  the  heavens,  that  we  cannot  imagine  a  part  of 
space  where  some  light  would  not  strike  the  eye : 
innumerable  stars — thousands  of  double  and  mul- 
tiple systems — clusters  in  one  blaze  with  their  ten 
thousands  of  stars — and  the  nebulre  amazing  us  by 
the  strangeness  of  their  forms  ;  till  at  last,  from  the 
imperfection  of  our  senses,  even  these  thin  and  airy 
phantoms  vanish  in  the  distance.  If  such  remote 
bodies  shone  by  reflected  light,  we  should  be  un- 
conscious of  their  existence ;  each  star  must  then 
be  a  sun,  and  may  be  presumed  to  have  its  system 
of  planets,  satellites,  and  comets,  like  our  own  ;  and 
for  aught  we  know,  myriads  of  bodies  may  be  wan- 
dering in  space,  unseen  by  us,  of  whose  nature  we 
can  form  no  idea,  and  still  less  of  the  part  they 
perform  in  the  economy  of  the  universe.  Nor  is 
this  an  unwarranted  presumption  :  many  such  do 
come  within  the  sphere  of  the  earth's  attraction, 
are  ignited  by  the  velocity  with  which  they  pass 
through  the  atmosphere,  and  are  precipitated  with 
great  violence  to  the  earth.  The  fall  of  meteoric 
stones  is  much  more  frequent  than  is  generally 
believed :  hardly  a  year  passes  without  some  in- 
stances occurring ;  and  if  it  be  considered  that  only 
a  small  part  of  the  earth  is  inhabited,  it  may  be 
presumed  that  numbers  fall  into  the  ocean,  or  on 
D 


34  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

the  uninhabited  parts  of  the  land,  unseen  by  man. 
They  are  sometimes  of  great  magnitude  :  the  volume 
of  several  has  exceeded  that  of  the  planet  Ceres, 
which  is   about  seventy  miles  in  diameter.     One 
which  passed  within  twenty-five  miles  of  us  was 
estimated  to  weigh  about  six  hundred  thousand  tons, 
and  to  move  with  a  velocity  of  about  twenty  miles 
in  a  second — a  fragment  of  it  alone  reached  the 
earth.     The  obliquity  of  the  descent  of  meteorites, 
the  peculiar  substances  of  which  they  are  composed, 
and  the  explosion  attending  their  fall,  show  that 
they  are  foreign  to  our  planet.     Luminous  spots, 
altogether  independent  of  the   phases,   have  been 
seen  on  the  dark  parts  of  the  moon  ;  these  appear 
to  be  the  light  arising  from  the  eruption  of  vol- 
canoes ;  whence  it  has  been  supposed  that  meteorites 
have  been  projected  from  the  moon  by  the  impetus 
of  volcanic  eruption.      If  a  stone  were  projected 
from  the  moon  in  a  vertical  line  with  an  initial 
velocity  of  10,992  feet  in  a  second — a  velocity  but 
four  times  that  of  a  ball  when  first  discharged  from 
a  cannon — instead  of  falling  back  to  the  moon  by 
the  attraction  of  gravity,  it  would  come  within  the 
sphere  of  the  earth's  attraction,  and  revolve  around 
it  like  a  satellite.     These  bodies,  impelled  either  by 
the  direction  of  the  primitive  impulse,  or  by  the 
disturbing  action  of  the  sun,  might  ultimately  pene- 
trate the  earth's  atmosphere  and  arrive  at  its  surface. 
But  from  whatever   source   meteoric   stones   may 
come,  it  is  highly  probable  that  they  have  a  common 


§  27.  ORIGIN  OF  METEORITES.  35 

origin,  from  the  uniformity,  we  may  almost  say 
identity,  of  their  chemical  composition."* 

27.  ORIGIN  OF  METEORITES. — Von  Hoff,  in  an 
admirable  essay  on  the  origin  of  meteoric  stones,-)- 
observes,  that  although  it  is  demonstrated  mathe- 
matically, that  aerolites  and  masses  of  native  iron 
which  fall  from  the  air,  may  be  derived  from  the 
moon,  yet  the  weight  of  evidence  is  in  favour  of 
their  being  nebulous  matter  suddenly  condensed, 
and  descending  to  this  planet's  surface  when  this 
mysterious  process  takes  place  within  the  sphere  of 
the  earth's  attraction.  These  masses  present  a 
general  correspondence  in  their  structure  and  ap- 
pearance, having  (with  the  exception  of  native  iron) 
a  crystalline  character  internally,  and  externally  a 
black  slaggy  crust,  as  in  this  specimen  from  Nan- 
jenoy. 

Assuming  then  that  our  planet,  when  first  called 
into  being  by  the  fiat  of  the  Creator,  was  a  gaseous 
mass  "  without  form  and  void,"  and  destined  through 
indefinite  ages  to  undergo  mutations  which  were 
designed  ultimately  to  prepare  it  for  the  abode  of 
the  human  race,  we  proceed  to  investigate  the 
causes  and  effects  of  those  agencies  by  which  its 
surface  is  still  modified.  The  consideration  of  what 
Sir  John  Herschel  so  emphatically  terms  "  that 
mystery  of  mysteries,"  the  successive  appearance  of 

•    *  Connexion  of  the  Physical  Sciences,  p.  423.  4th  Edition, 
f  A  Translation   of  this   Memoir  appeared   in  Jameson's 
Edinburgh  New  Philosophical  Journal,  July  1837. 
D  2 


36  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

new  forms   of  organic  'ife   on  our  globe,  will  be 
reserved  for  the  concluding  lecture. 

28.  EXISTING  GEOLOGICAL  CHANGES. — In  this 
division  of  the  subject,  it  will  be  my  object  to 
explain  in  a  clear  and  familiar  manner  some  of  those 
physical  changes  which,  unheeded  or  Unappreciated, 
are  taking  place  around  us ;  but  which  operating 
on  a  large  scale,  and  through  a  long  period  of  time, 
are  capable  of  producing  effects  that  materially 
modify  the  earth's  surface,  and  give  rise  to  results 
which,  when  viewed  in  the  aggregate,  fill  the  unin- 
formed mind  with  astonishment,  and  cause  it  to 
call  up  imaginary  convulsions  and  catastrophes  to 
explain  the  result  of  some  of  the  most  simple  ope- 
rations of  nature.  As  the  mere  lines  that  compose 
the  alphabet  constitute,  when  placed  in  combination, 
the  mighty  engine  by  which  the  master  spirits  of 
our  race  enlighten  and  benefit  mankind  ;  so  natural 
processes,  in  themselves  apparently  inadequate  to 
produce  any  important  effects,  become,  by  their  com- 
bined and  continued  operation,  an  irresistible  power. 
by  which  the  dry  land  is  converted  into  the  bed  of 
the  ocean,  and  the  bed  of  the  ocean  into  dry  land  ; 
thus  fulfilling  that  universal  law  of  the  Creator, 
which  subjects  every  particle  of  matter  to  incessant 
change. 

Before  proceeding  farther  in  this  inquiry,  I  would 
notice  an  opinion,  so  generally  prevalent  that  it  may 
possibly  be  entertained  by  some  present,  namely, 
that  the  phenomena  which  will  come  under  our 


§  28.  EXISTING  GEOLOGICAL  CHANGES.  37 

consideration,  have  been  produced  by  the  deluge 
recorded  in  Scripture.  But  whatever  may  have 
been  the  modifications  of  the  earth's  surface  pro- 
duced by  that  catastrophe,  they  must  on  the  present 
occasion  be  wholly  excluded  from  our  considera- 
tion, for  the  changes  to  which  geological  inquiries 
relate  are  of  a  totally  different  character,  and  refer- 
able to  periods  long  antecedent  to  that  miraculous 
event. 

I  have  now  to  direct  your  attention  to  those 
natural  operations  which,  when  properly  investi- 
gated, will  afford  an  easy  explanation  of  facts  of  the 
highest  interest  and  importance ;  will  teach  us  how 
this  limestone  has  been  formed  of  brittle  shells,  and 
this  marble  filled  with  the  coral  to  which  it  owes 
its  beautiful  markings — how  wood  has  been  changed 
into  stone,  and  plants  and  fishes  have  become  in- 
closed in  the  solid  rock.  I  wish  to  explain  to  you  that 
the  ground  on  which  we  stand  was  not  always  dry 
land,  but  once  constituted  the  bed  of  the  sea — that 
the  hills,  now  so  smooth  and  rounded,  and  clothed 
with  beautiful  verdure,  have  been  formed  in  the 
profound  depths  of  the  ocean,  and  may  be  regarded 
as  vast  tumuli,  in  which  the  remains  of  beings  that 
lived  and  died  in  the  early  ages  of  the  globe  are  en- 
tombed j— and  that  the  weald  of  Kent  and  Sussex, 
that  rich  and  cultivated  district  which  fills  up  the 
area  between  the  chalk  hills  of  Sussex,  Surrey, 
Kent,  and  Hampshire,  was  once  the  delta  of  a  river, 
that  flowed  through  a  country  which  is  now  swept 


38  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

from  the  face  of  the  earth — a  country  more  mar- 
vellous than  any  that  even  romance  or  poetry  has 
ventured  to  portray. 

29.  EFFECTS  OF  STREAMS  AND  RIVERS.  —  In 
pursuance  of  this  object  I  shall  first  take  into  con- 
sideration the  action  of  running  water — of  streams, 
and  rivers.  I  need  not  dwell  on  those  meteoro- 
logical causes  by  which  the  descent  of  moisture  on 
the  surface  of  the  earth  is  regulated  ;  but  shall 
content  myself  with  observing,  that  rivers  are  the 
great  natural  outlets  which  convey  the  superfluous 
moisture  of  the  land  into  the  grand  reservoir,  the 
ocean.  And  so  exactly  is  the  balance  of  expenditure 
and  supply  maintained,  that  all  the  rivers  on  the 
face  of  the  earth,  though  constantly  pouring  their 
mighty  floods  into  the  ocean,  do  not  affect  its  level 
in  the  slightest  perceptible  degree ;  we  may  there- 
fore assume  that  the  quantity  of  moisture  evaporated 
from  the  surface  of  the  sea,  is  exactly  equal  to  the 
sum  of  all  the  water,  in  all  the  rivers  in  the  world. 
But  although  the  body  of  fresh-water  poured  by  the 
rivers  into  the  basin  of  the  ocean  is  again  displaced 
by  evaporation,  yet  there  is  an  operation  silently 
and  constantly  going  on,  which  becomes  an  agent  of 
perpetual  change.  The  rivulets  which  issue  from 
the  mountains  are  more  or  less  charged  with  earthy 
particles,  worn  from  the  rocks  and  strata  over  which 
they  flow:  their  united  streams  in  their  progress 
towards  the  rivers  become  more  and  more  loaded 
with  adventitious  matter ;  and  as  the  power  of 


$  30.  EFFECTS  OF  STREAMS  AND  RIVERS.  39 

abrasion  becomes  greater,  by  the  increase  in  the 
quantity  and  density  of  the  mass  of  water,  a  large 
proportion  of  materials  is  mechanically  or  chemi- 
cally suspended  in  the  fluid,  and  carried  into  the 
sea.  If  the  current  be  feeble,  much  of  the  mud, 
and  the  larger  pebbles,  will  be  thrown  down  in  the 
bed  of  the  river — hence  the  formation  of  the  alluvial 
plains  in  the  valleys  of  the  Arun,  the  Adur,  the 
Ouse,  and  Cuckmere,  in  this  county.*  But  the 
greater  portion  will  be  transported  to  the  mouths 
of  the  rivers,  and  there  form  those  accumulations 
of  the  fluviatile  spoils  of  the  land  which  constitute 
deltas ;  the  finest  particles,  however,  will  be  carried 
far  into  the  sea,  and,  transported  by  currents  and 
agitated  by  the  waves,  will  at  length  be  precipitated 
into  the  profound  and  tranquil  depths  of  the  ocean. 
But  the  waters  convey  not  only  the  mud  and  water- 
worn  materials  of  the  country  over  which  they 
flow:  leaves,  branches  of  trees,  and  other  vegetable 
matter — and  the  remains  of  the  animals  that  fall 
into  the  streams,  with  shells  and  other  exuviae, 
human  remains,  and  works  of  art,  are  also  con- 
stantly transported  and  imbedded  in  the  mud,  silt, 
and  sand  of  the  delta,  some  of  these  remains  being 
occasionally  drifted  out  to  sea,  and  deposited  in 
its  bed. 

30.  DELTAS  OF  THE  GANGES,  AND  MISSISSIPPI. 
— The  changes  here  contemplated,  as  they  are  going 

*  Sussex. 


40  THE  WONDERS  OF  GEOLOGY.  LECI.  I. 

on  in  our  own  island,  may  appear  insignificant,  and 
incapable  of  producing  any  material  effect  on  the 
earth's  surface ;  but  if  we  trace  the  results  in 
countries  where  these  agents  are  now  operating  on 
a  larger  scale,  we  shall  at  once  perceive  their  im- 
portance, and  that  time  only  is  wanting,  to  form 
accumulations  of  strata,  equal  in  extent,  and  of 
the  same  character  with  many  of  those  ancient 
deposits,  which  will  hereafter  come  under  our  ob- 
servation. 

From  experiments  made  with  great  care,  it  has 
been  ascertained  that  the  quantity  of  solid  matter 
brought  down  by  the  Ganges  and  carried  into  the 
sea  annually,  is  equal  to  6,368,077,440  tons :  in 
other  words,  to  a  mass  of  solid  materials,  equal  in 
size  and  weight  to  sixty  times  that  of  the  great 
pyramid  of  Egypt ;  the  base  of  that  stupendous 
structure  covering  eleven  acres,  and  its  perpendicular 
height  being  500  feet.*  The  Burrampooter,  another 
river  in  India,  conveys  annually  as  much  earthy 
matter  into  the  sea  as  the  Ganges.  The  waters  of 
the  Indus,  as  the  celebrated  traveller,  Captain  Burns, 
informed  me,  are  alike  loaded  with  earthy  materials. 

In  the  mighty  rivers  of  America,  the  same  effects 
are  observable;  the  quantities  of  trees  brought  down 
by  the  Mississippi  and  imbedded  in  its  deposits  are 
almost  incredible,  and  the  basin  of  the  sea  around 
the  embouchure  of  that  river,  is  becoming  shallower 

*  Lyell's  Principles  of  Geology. 


§  30.         DELTAS  OF  THE  GANGES  AND  MISSISSIPPI.  41 

every  day,  by  the  sole  agency  of  the  operations  now 
under  consideration.  In  the  sediments  of  these 
rivers,  the  animals  as  well  as  the  plants  of  the  re- 
spective countries  are  continually  enveloped.  It  is 
therefore  evident,  that  should  these  deltas  become 
dry  land,  the  naturalist  could,  by  an  examination  of 
the  animal  and  vegetable  remains  imbedded  in  the 
fluviatile  sediments,  readily  determine  the  characters 
of  the  fauna  and  flora  of  the  countries  through 
which  the  rivers  had  flowed.  We  may  here  observe, 
that  in  tropical  regions,  where  animal  life  is  pro- 
fusely developed,  and  but  little  under  the  control  of 
man,  the  animal  remains  buried  in  deltas,  are  far 
more  abundant  than  in  those  of  European  countries, 
which  are  thickly  peopled,  and  in  a  high  state  of 
civilization.  The  enterprising,  but  unfortunate 
Lander  informed  me,  just  before  he  embarked  on 
his  last  fatal  expedition  to  Africa,  that  many  parts 
of  the  Quorra,  or  Niger,  so  far  as  the  eye  could 
reach,  teemed  with  crocodiles  and  hippopotami ;  and 
so  great  was  their  number,  that  he  was  oftentimes 
obliged  to  drag  his  boat  on  shore  lest  it  should  be 
swamped  by  these  animals.  But  it  is  unnecessary 
for  me  to  dwell  longer  on  these  operations  ;  it  will 
suffice  to  have  shown,  that  by  the  simple  effect  of 
running  water,  great  destruction  and  modification 
of  the  surface  of  the  land  are  everywhere  taking 
place ;  and  at  the  same  time,  fluviatile  deposits 
are  forming  on  an  extensive  scale,  and  enveloping 
animal  and  vegetable  remains.  Thus,  in  the  deltas 


42  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

of  the  rivers  of  this  country,  we  find  the  bones  and 
antlers  of  the  deer,  horse,  and  other  domesticated 
animals,  with  the  trunks  and  branches  of  trees  and 
plants  of  our  island,  river  and  land  shells,  human 
bones,  fragments  of  pottery  and  other  works  of 
art :  while  in  those  of  the  Ganges  and  the  Nile,  the 
remains  of  the  animals  and  vegetables  of  India  and 
of  Egypt  are  respectively  entombed. 

31.  FORMATION  OF  STRATA.  —  There  is  one 
circumstance  connected  with  these  facts  which  it 
will  be  necessary  here  to  consider.  The  quantity 
of  water  in  streams  and  rivers  varies  considerably 
at  different  periods  of  the  year ;  in  the  rainy  season 
the  rivers  are  overflowing,  and  the  waters  remark- 
ably turbid  :  the  depositions,  therefore,  must  be 
much  greater  at  those  periods  than  in  the  summer 
months,  when  the  streams  are  feeble,  and  the  rivers 
shallow.  In  that  part  of  the  river  affected  by  the 
tides,  there  is  also  a  constant  flux  and  reflux  of  the 
waters,  and  from  these  causes  the  depositions  must, 
to  a  certain  degree,  be  periodical.  Accordingly  we 
find  them  disposed  in  strata  or  layers,  from  the 
partial  consolidation  of  the  surface  of  one  bed  of 
mud,  before  the  superincumbent  layer  was  pre- 
cipitated upon  it.  Thus  wherever  a  fresh  break 
takes  place  in  a  bank  of  consolidated  mud,  in  the 
delta  of  the  Nile,  it  is  easy  to  trace  the  deposits  of 
each  successive  year,  by  means  of  the  lighter  earth 
on  the  top  of  each.  When  a  portion  is  taken  into 
the  hand,  it  separates  into  layers ;  and  on  closely 


§  32.  RIPPLED  SAND.  43 

examining  the  edges  of  these,  very  delicate  thin 
lines  are  perceptible,  showing  a  laminated  structure, 
like  those  observable  in  the  coal-shales.  Judging 
from  these  layers,  the  annual  deposits  appear  to 
vary  considerably,  but  the  average  thickness  is  little 
more  than  a  quarter  of  an  inch.* 

Where  a  river  terminates  in  an  extensive  estuary, 
the  sea  throws  over  the  layer  of  mud  brought  down 
by  the  river,  a  covering  of  sand :  and  frequently 
these  alternate  with  the  greatest  regularity,  the  re- 
ceding of  the  tide  allowing  the  fresh  water  to  deposit 
its  mud,  and  the  advance  of  the  sea  discharging  sand 
and  marine  exuvise  over  the  surface. 

32.  RIPPLED  SAND. — And  here  we  may  notice 
another  phenomenon.  Every  one  must  have  ob- 
served, when  walking  by  the  banks  of  a  river  at  low 
water,  or  on  the  sands  of  the  sea-shore,  that  when 
the  water  has  been  agitated  by  the  wind,  the  surface 
of  the  mud,  or  sand,  is  undulated,  or  furrowed  over 
by  the  rippling  of  the  waves,  the  marks  presenting 
various  appearances,  according  to  the  force  and  di- 
rection of  the  currents.  Frequently  too,  the  vermes 
and  molluscous  animals  mark  the  surface  with 
meandering  lines,  and  ridges ;  and  these  varied 
markings  on  the  sand  are  preserved,  if  a  thin 
layer  of  mud  happen  to  be  deposited  over  them 
before  the  next  advance  of  the  waves.  I  shall  have 

*  Letter  to  Professor  Silliman  from  an  American  who  visited 
Egypt  in  1834. 


44  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

occasion  to  refer  to  t'lese  appearances  hereafter. 
We  must  also  remark  that  there  are  certain  kinds 
of  mollusca,  or  shell- fish,  that  can  only  live  in  fresh 
water ;  others  that  are  confined  to  the  sea ;  while  a 
third  class  is  restricted  to  the  brackish  waters  of 
estuaries.  Accordingly,  in  the  deposits  under  con- 
sideration, the  river  and  estuary  species  are  abundant, 
while  the  marine  only  occur  as  stragglers,  and  are 
comparatively  rare.  Land  plants,  and  those  which 
affect  a  marshy  soil,  as  the  equiseta,  or  mare's-tails, 
reeds,  rushes,  &c.  are  likewise  often  accumulated  in 
such  quantities  as  to  form  beds  of  peat. 

33.  LEWES  LEVELS. — It  will  serve  to  impress  the 
subject  more  forcibly  upon  our  minds,  if  we  refer  to 
some  local  example  of  fluviatile  deposits :  and  from 
its  immediate  vicinity  to  Brighton,  I  select  the 
valley  of  the  Ouse,  between  Newhaven  and  Lewes, 
which  is  one  of  several  estuaries  from  whence  the 
sea  has  retired  within  the  last  eight  or  ten  centuries. 
This  valley  is  bounded  by  an  amphitheatre  of  chalk 
hills,  into  which  the  river  enters  through  a  gorge  of 
the  Downs  on  the  north,  and  pursuing  a  tortuous 
course,  discharges  its  waters  at  Newhaven.  This 
alluvial  plain  is  called  Lewes  Levels,  and  is  here 
and  there  flanked  by  headlands,  and  ancient  cliffs ; 
while  a  few  insular  mounds  of  chalk  rise  up  through 
the  fluviatile  depositions,  which  have  been  accumu- 
lating during  a  long  period  of  time.  The  following 
diagram  represents  a  section  of  the  valley  of  the 
Ouse,  from  east  to  west. 


§  33.  LEWES  LEVELS.  45 

Here  we   have  a  depression   (or  basin,  as  it  is 
termed  by  geologists)  of  the  chalk,  partially  filled 


TAB.  7.— VERTICAL  SECTION  OF  LEWES  LEVELS.* 

up  by  layers  of  indurated  mud  or  silt,  the  surface 
of  which  is  clothed  with  verdure;  the  bed  of  the 
river  (i.)  is  situated  near  the  eastern  chalk  cliffs. 
The  deposits  which  repose  on  the  chalk  are  as 
follow : — 

1 .  A  bed  of  peat  about  five  feet  in  thickness : 
formed  of  decayed  twigs  and  leaves  of  the  hazel, 
oak,  birch,  &c.  inclosing  trunks  of  large  trees. 

2.  (A.  A.) — Blue  clay,   or  indurated  mud,   con- 
taining several  species  of  fresh-water  shells,  like 
those  which  now  inhabit   the  river  and   ditches  ; 
with    numerous    indusice,    or   cases   of    the   larvae 

*  A  geological  section  represents  the  internal  structure  of  the 
earth  on  any  given  line,  in  a  vertical  direction  ;  and  is  either 
(1)  natural,  as  seen  in  cliffs,  precipices,  &c.;  (2)  artificial,  as  in 
quarries,  tunnels,  and  other  excavations ;  or  (3)  ideal,  when 
constructed  from  combinations  of  observations  on  the  position 
of  strata  in  various  localities. 


46  -          THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

of  phryganecB,  or  cad'1  is- worms.  Bones  of  the 
horse,  and  deer,  also  occur  in  the  lower  part  of 
this  bed. 

3.  (B.  B.) — Clay,   containing  fresh- water  shells, 
with  an  intermixture  of  existing  marine  species,  as 
the  common  cockle,  (cardium  edule,)  tellina,  &c. 

4.  (c.  c.) — Blue  clay,  inclosing  marine  shells,  viz. 
cockles,  muscles,  &c.  without  any  intermixture  of 
fluviatile  species.    In  this  bed  a  skull  of  the  narwal, 
or  sea-unicorn  (Monodon  monoceros,)  and  of  the 
porpoise  have  been  discovered. 

From  the  nature  of  these  deposits  we  learn  that 
this  valley  was  once  an  arm  of  the  sea,  and  that  the 
sequence  of  the  physical  changes  which  took  place 
was  as  follows  : — 

First,  There  was  a  salt-water  estuary,  inhabited 
by  marine  shell-fish  of  the  same  species  as  those 
now  existing  in  the  British  Channel ;  and  into  which 
cetacea  occasionally  entered. 

Secondly,  The  inlet  grew  shallow,  the  water 
brackish,  and  marine  and  fresh-water  shells  were 
mingled  in  its  blue  argillaceous  sediment. 

Thirdly,  The  shoaling  continued  until  fresh- 
water so  much  predominated,  that  fluviatile  shells, 
and  aquatic  insects,  could  alone  exist. 

Fourthly,  A  peaty  swamp,  or  morass  was  formed, 
by  the  drifting  of  trees,  and  plants,  from  the  forest 
of  Andreadswald,  which  formerly  occupied  the  weald 
of  Sussex  ;  and  terrestrial  quadrupeds  were  occa- 
sionally imbedded. 


§  34.  REMAINS  OF  MAN  IN  ALLUVIUM.  47 

Lastly,  The  soil  being  inundated  by  land  floods 
at  distant  intervals  only,  became  a  verdant  marshy 
plain.* 

34%  REMAINS  OF  MAN  IN  MODERN  ALLUVIUM. 
— But  the  sediments  in  the  river  valleys  of  the 
South  Downs  often  contain  not  only  the  bones  of 
the  deer,  horse,  boar,  and  other  terrestrial  animals, 
but  also  human  skeletons,  which  are  sometimes 
found  inclosed  in  coffins  of  exceedingly  rude  work- 
manship :  together  with  canoes,-)-  and  other  relics 

*  Geology  of  the  South-east  of  England,  p.  16. 

t  Ancient  British  Canoe.  In  1835  a  canoe  was  discovered  at 
the  depth  of  several  feet  in  a  bed  of  silt,  occupying  an  ancient 
branch  of  the  river  Arun,  at  North  Stoke,  near  Arundel.  It 
was  presented,  by  my  noble  friend  the  late  Earl  of  Egremont, 
to  the  British  Museum  ;  and  is  placed  on  the  right  hand  of  the 
entrance  of  the  court.  This  canoe  is  nearly  thirty -five  feet  in 
length,  four  and  a  half  wide  in  the  centre,  three  feet  three  inches 
broad  at  one  extremity,  and  two  feet  ten  inches  at  the  other ;  and 
is  about  two  feet  deep.  It  is  formed  of  the  single  trunk  of  an  oak, 
which  has  been  hollowed  out  and  brought  to  its  present  shape 
with  great  labour  ;  it  is  evidently  the  workmanship  of  a  very 
remote  period,  and  in  all  probability  was  constructed  by  some  of 
the  earliest  inhabitants  of  our  island,  before  the  use  of  iron  or 
even  brass  was  known :  the  original  tree  must  have  been  fifteen 
or  sixteen  feet  in  circumference.  Three  projections,  left  in  the 
interior  of  the  boat,  appear  to  have  been  designed  for  seats  ;  it 
is  manifest  therefore  that  the  persons  who  constructed  this  vessel 
were  unacquainted  with  the  art  of  forming  boards.  This  canoe 
is  so  similar  to  some  of  those  which  were  fabricated  by  the 
aborigines  of  North  America,  when  first  visited  by  Europeans, 
that  we  can  have  no  hesitation  in  concluding  that  it  was  con- 
structed in  a  similar  manner ;  namely,  by  charring  such  portions 
of  the  tree  as  were  to  be  removed,  and  scooping  them  out  with 


48  THE  WONDERS  OF  GEOLOGY.  LKCT.  I. 

of  the  early  inhabitants  of  our  island.  This  human 
skull,  for  which  I  am  indebted  to  Warren  Lee,  Esq. 
of  Lewes,  was  dug  up  at  a  great  depth  in  the  blue 
silt  of  Beeding  Levels ;  it  was  inclosed,  together 
with  the  other  bones  of  the  skeleton,  in  a  coffin  of 
oak,  which  was  evidently  of  high  antiquity,  being 
formed  of  four  rude  planks,  or  rather  squared  trunks 
of  trees,  held  together  by  oaken  pegs.  The  skull 
is  of  a  dark  bluish-brown  colour,  like  the  bones  of 
the  deer  and  horse  of  similar  deposits  ;  an  appear- 
ance attributable  to  an  impregnation  of  iron  ;  when 
first  dug  up,  blue  phosphate  of  iron  filled  up  the 
interstices  of  the  bones.  The  state  of  the  teeth  is 
remarkable;  they  are  worn  down  almost  smooth, 
although  the  individual  must  have  been  in  the  prime 
of  life ;  a  fact  which  seems  to  indicate  that  grain, 
or  some  other  hard  substance,  constituted  a  large 
proportion  of  his  customary  food. 

35.  PEAT  BOGS. — Before  proceeding  to  the  next 
subject,  I  will  advert  to  those  extensive  accumula- 
tions of  vegetable  matter  called  Peat  Bogs.  These 
are  morasses,  covered  with  successive  layers  or  beds 
of  mosses,  reeds,  equiseta,  rushes,  and  other  plants 
that  affect  a  marshy  soil ;  and  in  particular  of  a  kind 
of  moss,  the  sphagnum  palustre,  which  frequently 
constitutes  a  large  proportion  of  the  entire  mass. 

stone  instruments  :  no  doubt  this  canoe  belongs  to  the  same 
period  as  the  flint  and  stone  instruments  called  celts,  which  are 
found  in  the  tumuli  on  the  South  Downs  ;  it  is  now  in  the  state 
of  peat  or  bog- wood. 


§  36.  PEAT  BOGS.  49 

The  beds  of  peat  are  annually  augmented  by  the 
peculiar  mode  of  increase  of  the  peat-moss,  which 
throws  up  a  succession  of  shoots  to  the  surface, 
while  the  parent  plants  decay,  and  form  a  new  layer 
of  the  soil. 

The  peat  bogs  of  Ireland  are  of  great  extent : 
one  of  the  mosses  on  the  banks  of  the  Shannon  is 
two  or  three  miles  in  breadth,  and  fifty  in  length. 
Mr.  Lyell  remarks,  that  the  peat-mosses  of  the 
North  of  Europe  occupy  the  areas  of  the  ancient 
forests  of  oak  and  pine ;  and  that  the  fall  of  trees 
from  the  effect  of  storms,  or  natural  decay,  by  ob- 
structing the  draining  of  a  district,  and  thus  giving 
rise  to  a  marsh,  is  the  origin  of  most  of  the  peat 
bogs ;  mosses,  and  other  marsh  plants,  spring  up, 
and  soon  overwhelm  and  bury  the  prostrate  forests ; 
hence  the  occurrence  of  trunks  and  branches  of  enor- 
mous oaks,  firs,  &c.  with  their  fruits. 

De  Luc  states,  that  the  sites  of  many  of  the  ab- 
original forests  on  the  continent  are  now  covered  by 
mosses  and  fens,  and  that  many  of  these  changes 
are  attributable  to  the  destruction  of  the  forests  by 
the  Romans.  A  remarkable  fact  relating  to  peat 
bogs  must  not  be  omitted  ;  namely,  the  occasional 
occurrence  of  the  bodies  of  men  and  animals,  in  a 
high  state  of  preservation,  at  a  great  depth.  In 
some  instances  the  bodies  are  converted  into  a  fatty 
substance,  resembling  spermaceti,  called  adipocire. 

36.    CONVERSION  OF   PEAT   INTO   COAL.* — A 

*  Dr.  Jackson  on  the  Geology  of  Maine. 
E 


50  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

fact  of  great  geological  interest  is  the  occurrence  of 
coal  in  peat  bogs,  since  it  proves  that  the  conver- 
sion of  vegetable  matter  into  a  mineral,  the  origin 
of  which  was  formerly  deemed  questionable,  takes 
place,  wherever  circumstances  are  favourable  for 
the  production  of  the  bituminous  fermentation.  In 
Limerick,  in  the  district  of  Maine,  one  of  the  States 
of  North  America,  there  are  peat  bogs  of  consider- 
able extent,  in  which  a  substance  exactly  similar  to 
cannel  coal  is  found  at  the  depth  of  three  or  four 
feet  from  the  surface,  amidst  the  remains  of  rotten 
logs  of  wood,  and  beaver  sticks  :  the  peat  is  twenty 
feet  thick,  and  rests  upon  white  sand.  This  coal 
was  discovered  on  digging  a  ditch  to  drain  a  por- 
tion of  the  bog,  for  the  purpose  of  obtaining  peat 
for  manure.  The  substance  is  a  true  bituminous 
coal,  containing  more  bitumen  than  is  found  in  any 
other  variety.*  Polished  sections  of  the  compact 
masses  exhibit  the  peculiar  structure  of  coniferous 
trees,  and  prove  that  the  coal  was  derived  from  a 
species  allied  to  the  American  fir.  It  has  probably 
been  formed  by  the  chemical  changes  supervening 
upon  fir-balsam,  during  its  long  immersion  in  the 

*  An  analysis  of  100  grains  gave  the  following  results  : 

Bitumen 72 

Carbon 21 

Oxide  of  iron    ....       4 

Silica 1 

Oxide  of  Manganese       .       2 

100 


§37,35.  SUBTERRANEAN  FORESTS.  51 

humid  peat ;  the  circumstances  under  which  it  was 
placed  being  most  favourable  for  that  process  to  take 
place,  by  which,  as  we  shall  show  hereafter  (see  Lec- 
ture VI.),  vegetable  matter  is  converted  into  coal. 

37.    SUBTERRANEAN   FORESTS. — Independently 
of  the  trees  immersed  in  peat  bogs  and  morasses, 
there  are  also  found  entire  forests  buried  deeply  in  the 
soil ;  the  trees  having  their  roots,  trunks,  branches, 
fruits,  and  even  leaves,  more  or  less  perfectly  pre- 
served.    Several  accumulations  of  this  kind  have 
been  discovered  on  the  coast  of  Sussex,  occupying 
low  alluvial  plains,  that  are  still  subject  to  periodical 
inundations.*      The  trees  are  chiefly  of  the  oak, 
hazel,  fir,  birch,  yew,  willow,  and  ash  ;    in  short, 
almost  every  kind  that  is  indigenous  to  this  island 
occasionally  occurs.     The  trunks,  branches,  &c.  are 
dyed  throughout  of  a  deep  ebony  colour  by  iron  ; 
and  the  wood  is  firm  and  heavy,   and  sometimes 
sufficiently  sound  for  domestic  use.     In  Yorkshire 
it  is  employed  in  the  construction  of  houses.     The 
specimens  which  I  now  place  before  you,  for  which 
I  am  indebted  to  Professor  Babbage,  exhibit  the 
usual  characters  of  such  remains  ;  they  are  portions 
of  large  trunks  of  yew,  oak,  and  fir,  from  a  peat 
bog  in  Ireland. 

38.     GEOLOGICAL    EFFECTS    OF    THE    SEA. — 
While  the  mountains,   valleys,  and  plains  of  the 
interior  of  a  country,  are  undergoing  slow  but  per- 
petual change  by  the  combined  effects  of  atmospheric 
*  See  Illustrations  of  the  Geology  of  Sussex,  p.  288. 
E2 


52  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

agency,  and  of  running  water,  the  coasts,  and  shores, 
are  exposed  to  destruction  from  the  action  of  the 
waves,  and  the  encroachments  of  the  sea.  When 
the  land  presents  a  high  and  rocky  coast,  the  waves, 
by  their  incessant  action,  undermine  the  cliffs,  which 
at  length  fall  down,  and  cover  the  shore  with  their 
ruins.  The  softer  parts  of  the  strata,  as  the  chalk, 
marl,  clay,  &c.  are  rapidly  disintegrated  and  washed 
away;  while  the  more  solid  materials  are  broken, 
and  founded,  by  the  continual  agitation  of  the  water, 
and  give  rise  to  those  accumulations  of  beach  and 
sand  which  skirt  our  sea-cliffs,  and  serve,  in  some 
situations,  to  protect  the  land  from  further  en- 
croachments. But  when  the  cliffs  are  entirely  com- 
posed of  soft  substances,  their  destruction  is  very 
rapid,  unless  artificial  means  be  employed  for  their 
protection ;  which,  however,  in  many  instances  are 
wholly  ineffectual. 

The  encroachments  of  the  ocean  upon  the  land 
effected  by  this  operation,  often  give  rise  to  sudden 
and  extensive  inundations,  and  the  destruction  of 
whole  tracts  of  country.  Along  the  Sussex  coast  the 
inroads  of  the  sea  have  been  noticed  in  the  earliest 
historical  records  ;  and  the  site  of  the  ancient  town 
of  Brighton  has  been  entirely  swept  away,  the  sands, 
and  the  waves,  now  occupying  the  spot  where  the 
first  settlers  on  these  shores  fixed  their  habitations.* 
On  low  and  sandy  coasts,  the  waves  drive  the  loose 
and  lighter  materials  towards  the  land ;  and  the 
*  See  Geology  of  the  South-East  of  England,  p.  23. 


§  39.  BED  OP  THE  OCEAN.  53 

drifted  sand,  becoming  dry  at  the  reflux  of  the  tide, 
is  carried  by  the  wind  inland,  and  in  some  situ- 
ations is  accumulated  in  such_quantities  as  to  form 
ranges  of  hills,  which  in  their  progress  overwhelm 
fertile  tracts,  and  engulf  churches,  and  even  entire 
villages.  These  sand  banks  or  downs,  loose  and 
fluctuating  as  they  are  in  their  first  stage  of  ad- 
vancement, become,  under  certain  circumstances, 
fixed,  and  converted  into  solid  stone — a  process  to 
which  we  shall  presently  advert. 

39.  BED  OF  THE  OCEAN. — But  the  production 
of  beach,  gravel,  and  sand,  on  the  shores,  and  the 
drifting  of  sand  inland,  are  effects  far  less  important 
than  those  which  are  going  on  in  the  profound 
depths  of  the  ocean.  In  the  tranquil  bed  6f  the 
sea,  the  finer  materials,  held  in  mechanical  or  chemi- 
cal suspension  by  the  waters,  are  precipitated  and 
deposited,  enveloping  and  embedding  their  inha- 
bitants, together  with  the  remains  of  such  animals 
and  vegetables  of  the  land  as  may  be  floated  down 
by  the  streams  and  rivers.  But,  in  the  beautiful 
language  of  Mrs.  Hemans, — 

"  The  depths  have  more !     What  wealth  untold 

Far  down  and  shining  through  their  stillness  lies  ! 
They  have  the  starry  gems,  the  burning  gold, 
Won  from  a  thousand  royal  argosies  ! 

"  Yet  more — the  depths  have  more  !     Their  waves  have  roll'd 

Above  the  cities  of  a  world  gone  by — 
Sand  hath  filled  up  the  palaces  of  old, 
Sea-weed  o'ergrown  the  halls  of  revelry. 


•>4  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

"  To  them  the  love  of  womar  hath  gone  down, — 

Dark  flow  their  tides  o'er  manhood's  noble  head, 
O'er  youth's  bright  locks,  and  beauty's  flowery  crown." — 

Yes  !  in  these  modern  depositions,  the  remains  of 
man,  and  of  his  works,  must  of  necessity  be  con- 
tinually engulfed,  together  with  those  of  the  animals 
which  are  his  contemporaries. 

Of  the  nature  of  the  bed  of  the  ocean,  we  can 
of  course  know  but  little  from  actual  observation. 
Soundings,  however,  have  thrown  light  upon  the 
deposits  now  forming  in  those  depths,  which  are 
accessible  to  this  mode  of  investigation  ;  and  thus 
we  learn,  that  in  many  parts  immense  accumulations 
of  the  remains  of  testaceous  animals,  intermixed  with 
sand,  gravel,  and  mud,  are  going  on.  Donati  ascer- 
tained the  existence  of  a  compact  bed  of  shells,  100 
feet  in  thickness,  at  the  bottom  of  the  Adriatic, 
which  in  some  parts  was  converted  into  marble.  In 
the  British  Channel,  extensive  banks  of  sand,  im- 
bedding the  remains  of  shells,  Crustacea,  &c.  are  in 
the  progress  of  formation.  This  specimen,  which  was 
dredged  up  a  few  miles  from  land,  off  Brighton, 
is  an  aggregation  of  sand  with  recent  marine  shells, 
oysters,  muscles,  limpets,  cockles,  &c.  and  minute 
corallines  ;  and  this  example,  from  off  the  Isle  of 
Sheppey,  consists  entirely  of  cockles  (Cardium 
edule),  held  together  by  conglomerated  sand.  In 
bays  and  creeks,  bounded  by  granitic  rocks,  the 
bottom  is  found  to  be  composed  of  micaceous  and 
quartzose  sand,  consolidated  into  what  may  be 


§  40.  CURRENTS,  AND  THEIR  EFFECTS.  55 

termed  regenerated  granite.  Off  Cape  Frio,  on  the 
Brazilian  coast,  solid  masses  of  this  kind  were 
formed  in  a  few  months,  and  in  them  were  found 
imbedded,  dollars  and  other  treasures  from  the 
wreck  of  a  vessel,  to  recover  which  an  exploration 
by  the  diving  bell  was  undertaken. 

40.  CURRENTS,  AND  THEIR  EFFECTS. — The  dis- 
tribution over  the  bottom  of  the  sea  of  the  detritus 
brought  down  by  rivers  and  streams,  and  of  the 
materials  worn  away  by  the  action  of  the  waves  on 
the  shores,  is  principally  effected  by  the  influence  of 
currents,  which,  from  their  regularity,  permanency, 
and  extent,  may  be  considered  as  the  rivers  of  the 
ocean.  To  this  agency  I  can  but  briefly  allude,  and 
shall  restrict  my  remarks  to  the  Gulf-stream,  which 
is  the  great  current  that  transports  the  waters,  and 
the  temperature  of  the  tropical  regions,  into  the 
climates  of  the  north.  From  the  mouth  of  the 
Red  Sea  a  current  about  50  leagues  in  breadth  sets 
continually  towards  the  south  west ;  doubling  the 
Cape  of  Good  Hope,  it  assumes  a  north-west  direc- 
tion, and  in  the  parallel  of  St.  Helena,  its  breadth 
exceeds  1000  miles ;  then  taking  a  direction  nearly 
east,  it  meets  in  the  parallel  of  3°  north,  along  the 
northern  coast  of  Africa,  with  a  current  from  the 
north ;  entering  the  Gulf  of  Florida,  they  are  re- 
flected and  form  the  Gulf-stream,  which,  passing 
along  the  coast  of  North  America,  stretches  across 
the  Atlantic  to  the  British  Isles.  At  the  parallel  of 
38°,  nearly  1000  miles  from  the  Straits  of  Bahama, 


56  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

the  water  of  the  stream  is  ten  degrees  warmer 
than  the  air.  The  course  of  the  Gulf-stream  is  so 
fixed  and  regular,  that  nuts  and  plants  from  the 
West  Indies  are  annually  drifted  to  the  western 
islands  of  Scotland.  The  mast  of  a  man-of-war, 
burnt  at  Jamaica,  was  driven  ashore  several  months 
afterwards  on  the  Hebrides,  "after  performing  a 
voyage  of  more  than  4000  miles  under  the  direction 
of  a  current  which,  in  the  midst  of  the  ocean,  main- 
tains its  course  as  steadily  as  a  river  upon  the 
land."*  The  quantity  of  detritus  transported  by 
such  a  current  must  be  immense,  and  we  therefore 
need  not  wonder  at  frequently  finding  the  pro- 
ductions of  different  climates  associated  together 
in  a  fossil  state. 

41.  INCRUSTING  SPRINGS,  &c. — The  phenomena 
hitherto  considered,  are  referable  to  the  mechanical 
action  of  water;  and  the  effect  has  been  that  of 
disintegration,  and  destruction,  in  the  first  instance ; 
and  in  the  second,  of  accumulations  of  sediments  in 
water-channels,  and  in  the  bed  of  the  sea.  We 
must  now  refer  to  an  operation  of  a  totally  different 
character — the  power  possessed  by  streams,  as  clear 
and  sparkling  as  poet  ever  feigned,  or  sung,  of 
consolidating  loose  materials,  of  converting  porous 
strata  into  solid  stone,  and  of  filling  up  their 
own  channels  by  the  deposition  of  calcareous 
matter. 

That  most  fresh  water  holds  a  certain  proportion 
*  Playfair's  Works,  edition  1822  ;  vol.  i.  p.  414. 


§41.  INCRUSTING  SPRINGS.  57 

of  carbonate  of  lime*  in  solution,  is  well  known; 
and  also  that  changes  of  temperature,  as  well  as 
many  other  causes,  will  occasion  the  calcareous 
earth  to  be  in  part  or  wholly  precipitated.  The 
fur,  as  it  is  called,  that  lines  a  boiler  which 
has  been  long  in  use,  affords  a  familiar  illustration 
of  this  fact.  At  the  temperature  of  60°,  lime  is 
soluble  in  700  times  its  weight  of  water ;  and  if 
to  the  solution  a  small  portion  of  carbonic  acid  be 
added,  a  carbonate  of  lime  is  formed,  and  pre- 
cipitated in  an  insoluble  state.  If,  however,  the 
carbonic  acid  be  in  such  quantity  as  to  supersaturate 
the  lime,  it  is  again  rendered  soluble  in  water ;  and 
it  is  thus  that  carbonate  of  lime,  held  in  solution  by 
an  excess  of  fixed  air,  not  in  actual  combination 
with  the  lime,  but  contained  in  the  water  and  acting 
as  a  menstruum,  is  commonly  found  in  all  waters. 
An  absorption  of  carbonic  acid,  or  a  loss  of  that 
portion  which  exists  in  excess,  will  therefore  occasion 
the  calcareous  earth  to  be  set  free,  and  precipitated 
on  any  substances  in  the  water,  such  as  stones,  sprigs, 
and  leaves  of  trees,  &c.  Some  springs  contain  so 
large  a  proportion  of  calcareous  earth  when  they 
first  issue  from  the  rocks,  and  so  speedily  throw  it 
down  in  their  course,  that  advantage  has  been  taken 
of  the  circumstance  to  obtain  incrustations  of  various 

*  Carbonate  of  lime  consists  of  lime  in  combination  with 
carbonic  acid  gas,  which  is  a  most  abundant  natural  product. 
This  gas  is  unrespirable,  and  when  pure,  will  immediately  suf- 
focate an  animal  immersed  in  it.  It  extinguishes  flame. 


58  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

objects,  as  leaves,  brancnes,  baskets,  nests  with  eggs, 
and  even  old  wigs.  The  incrusting  springs  of  Der- 
byshire are  celebrated  for  such  productions.  These 
depositions  are  termed  tufa,  or  travertine ;  and  in 
Italy,  and  many  other  countries,  they  constitute 
extensive  beds  of  concretionary  limestone,  which 
is  often  of  a  crystalline  structure.  The  Cyclo- 
pean walls  and  temples  of  Paestum,  are  formed  of 
this  substance.  At  the  baths  of  San  Filippo,  in 
Tuscany,  where  the  waters  are  highly  charged  with 
tufa,  this  property  is  applied  to  a  very  ingenious 
purpose.  The  stream  is  directed  against  moulds  of 
medallions,  and  other  bas-reliefs,  and  very  beautiful 
casts  are  thus  obtained  ;  of  which  we  have  an  ex- 
ample in  this  medallion,  which  bears  the  head  of 
Napoleon,  and  was  presented  to  me  by  the  Marquis 
of  Northampton. 

42.  INCRUSTATIONS  NOT  PETRIFACTIONS. — As 
specimens  of  this  kind  are  commonly,  but  errone- 

A 


B 

TAB.  8. — INCRUSTATION. 
A  A  A,  Extremities  of  the  twig  unchanged;  B  B,  the  tufaceous  crusl. 

ously,   termed  petrifactions,  I  will  briefly  explain 
their   real   nature.      We    have    before   us   several 


§  42.  INCRUSTATIONS  NOT  PETRIFACTIONS.  59 

incrustations  from  various  places  :  baskets  of  shells, 
and  nests  with  eggs,  from  Derbyshire  ;  a  bird,  from 
Knaresborough,  in  Yorkshire ;  and  a  twig,  partially 
incrusted,  from  Ireland. 

I  need  scarcely  observe,  that  on  breaking  such 
specimens,  we  find  the  inclosed  substances  to  have 
undergone  no  change  but  that  of  decay,  in  a  greater 
or  less  degree.  In  this  incrusted  bird's  nest,  the 
twigs  of  which  it  is  composed,  like  the  branch  above 
mentioned,  are  exposed  in  several  places,  and,  as 
you  perceive,  are  not  permeated  by  stony  matter, 
but  are  dry,  and  brittle.  Now,  a  true  petrifaction 
is  altogether  of  a  different  nature,  the  substance 
being  saturated  throughout  with  mineral  matter ;  if 
we  break  it,  we  find  that  every  part  of  its  structure 
has  undergone  a  change  ;  sometimes  flint  has  filled 
up  the  interstices,  and  upon  slicing  and  polishing  it, 
the  most  delicate  texture  of  the  original  may  be  de- 
tected. Wood,  for  instance,  which  is  so  commonly 
petrified  by  flint  or  chalcedony,  may  be  cut  so  thin, 
that  with  a  powerful  lens  the  ramifications  of  the 
vessels  and  the  structure  of  the  tissues  may  be 
seen,  and  from  their  form,  and  disposition,  we  may 
determine  the  particular  kind  of  tree  to  which  the 
specimen  belonged,  although  it  may  have  been  cased 
up  in  stone  for  ages.  When  bone  is  petrified,  the 
same  phenomena  are  observable ;  the  most  delicate 
parts  of  the  internal  structure  are  preserved,  and 
all  the  cells  are  filled  up  with  stone  or  spar,  which 
is  oftentimes  of  a  different  colour  from  that  of  the 


60  THE  WOXDERS  OF  GEOLOGY.  LECT.  I. 

walls  of  the  cells,  and  thus  a  natural  anatomical  pre- 
paration, of  great  beauty  and  interest  is  formed. 

43.  LAKE  OF  THE  SOLFATARA. — The  celebrated 
lake  of  the  Solfatara  lies  in  the  Campagna  between 
Rome  and  Tivoli,  and  is  fed  by  a  stream  of  thermal 
water  which  flows  into  it  from  a  neighbouring  pool. 
The  water  is  of  a  high  temperature,  and  is  saturated 
with  carbonic  acid  gas,  which,  as  the  water  cools, 
is  constantly  escaping,  and  keeping  up  an  ebullition 
on  the  surface.  The  formation  of  travertine  is  so 
rapid,  that  not  only  the  vegetables  and  shell-fish 
are  surrounded  and  destroyed  by  the  calcareous 
deposition,  but  insects  also  are  frequently  incrusted. 
In  these  beautiful  specimens  of  travertine  from 
Solfatara,  vegetable  impressions  are  distinctly  seen, 
the  cavities  in  the  mass  having  been  occasioned  by 
the  decomposition  of  the  vegetable  matter.*  The 
stream  that  flows  out  of  the  lake  fills  a  canal,  which 
is  conspicuous  at  a  distance,  from  the  line  of  vapour 
emanating  from  the  water. 

A  considerable  number  of  the  edifices  of  both 
ancient  and  modern  Rome,  are  constructed  of  tra- 
vertine, derived  from  the  quarries  of  Ponte  Luccano, 
which  have  clearly  originated  from  a  lake  of  the 
same  kind.  Paestum  is  also  built  of  calcareous 
tufa,  derived  from  similar  deposits.  "  The  waters  of 
these  lakes,"  says  Sir  Humphry  Davy,  "  have  their 
rise  at  the  foot  of  the  Apennines,  and  hold  in  solu- 
tion carbonic  acid,  which  has  dissolved  a  portion  of 
*  See  Appendix  B. 


§  44.  MARBLE  OF  TABREEZ.  61 

the  calcareous  rocks  through  which  it  has  passed  ; 
the  carbonic  acid  is  dissipated  by  the  atmosphere, 
and  the  marble,  slowly  precipitated,  assumes  a  crys- 
talline form,  and  produces  coherent  stones.  The 
acid  originates  in  the  action  of  volcanic  fires  on  the 
calcareous  rocks  of  which  the  Apennines  are  com- 
posed, and  carbonic  acid  being  thus  evolved,  rises 
to  the  source  of  the  springs  derived  from  the  action 
of  the  atmosphere,  gives  them  their  impregnation, 
and  enables  them  to  dissolve  calcareous  matter." 

44.  MARBLE  OF  TABREEZ. — In  Persia,  a  beau- 
tiful transparent  limestone,  called  Tabreez  marble, 
is  formed  by  deposition  from  a  celebrated  spring 
near  Maragha,  where  the  whole  process  of  its 
formation  may  be  seen.  In  one  part  the  water  is 
clear,  in  another  dark,  muddy,  and  stagnant ;  in  a 
third  it  is  very  thick,  and  almost  black ;  while  in 
the  last  stage  it  is  of  a  snowy  whiteness.  The 
petrifying  pools  look  like  frozen  water:  a  stone 
thrown  on  them  breaks  the  crust,  and  the  water 
exudes  through  the  opening;  and  in  some  states 
the  process  has  proceeded  so  far  as  to  admit  of 
walking  on  the  surface  of  the  lake.  A  section  of 
the  stony  mass  resembles  an  accumulation  of  sheets 
of  paper,  being  finely  laminated ;  and  such  is  the 
tendency  of  this  water  to  solidify,  that  the  very 
bubbles  on  its  surface  become  hard,  as  if  they  had 
been  suddenly  arrested,  and  metamorphosed  into 
stone.* 

*  Morier's  Travels. 


62  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

45.  STALACTITES,  A^D  STALAGMITES. — By  the 
infiltration  of  water  through  limestone  rocks,  into 
fissures  and  cavities,  sparry  concretions  are  produced 
on  the  roofs,  sides,  and  floors  of  caverns.  The 
concretionary  masses  which  are  dependent  from 
the  roof  like  icicles,  are  called  stalactites ;  those 
which  form  on  the  floor,  from  the  droppings  of 
the  water,  are  termed  stalagmites;  and  when,  as 
frequently  happens,  the  two  unite,  a  singularly  pic- 
turesque effect  is  produced, — the  caves  appearing 
as  if  supported  by  pillars  of  the  most  extraordinary 
beauty  and  variety.*  Sometimes  a  linear  fissure  in 
the  roof,  by  the  direction  it  gives  to  the  dropping 
of  the  lapidifying  water,  forms  a  transparent  curtain 
or  partition.  A  remarkable  instance  of  this  kind 
occurs  in  a  cavern  in  North  America,  called  Weyer's 
Cave,  which  is  situated  in  the  limestone  range  of  the 
Blue  Mountains.-)-  There  are  also  many  caverns  in 
England,  celebrated  for  the  variety  and  beauty  of 
their  sparry  ornaments :  those  in  Derbyshire  are 
well  known. 

46.  GROTTO  OF  ANTIPAROS. — The  Grotto  of 
Antiparos  in  the  Grecian  Archipelago,  not  far  from 
Paros,  is  justly  admired.  The  sides  and  roof  of  its 
principal  cavity  are  covered  with  immense  in- 
crustations of  calcareous  matter,  which  form  either 
stalactites,  depending  from  above,  or  irregular  pillars 
rising  from  the  floor.  Several  perfect  columns 
reaching  to  the  ceiling  have  been  formed,  and  others 
*  Appendix  C.  f  Appendix  D. 


§  46.  GROTTO  OF  ANTIPAROS.  (};j 

are  still  in  the  course  of  formation,  by  the  union  of 
the  stalactite  from  above,  with  the  stalagmite  below. 
These  being  composed  of  matter  slowly  deposited, 
have  assumed  the  most  fantastic  shapes ;  while  the 
pure,  white,  and  glittering  spar,  beautifully  catches 
and  reflects  the  light  of  the  torches  of  the  visitors 
to  this  subterranean  palace,  in  a  manner  which 
causes  all  astonishment  to  cease  at  the  romantic 
tales  told  of  the  place — of  its  caves  of  diamonds, 
and  of  its  ruby  walls;  the  simple  truth,  when  de- 
prived of  all  exaggeration,  being  sufficient  to  excite 
admiration,  and  awe.  Some  of  these  concretions 
form  a  thin  curtain,  which  is  perfectly  trans- 
parent. 

The  specimens  which  I  have  selected  from  my 
collection,  to  illustrate  these  remarks,  exhibit  the 
usual  character  of  stalactitical  concretions  ;  those 
long  stony  icicles  are  from  Portland  ;  and  these 
minute  straws  of  spar,  from  an  archway  near  the 
Chain  Pier,  have  been  formed  by  the  infiltration  of 
rain  through  the  superincumbent  bed  of  calcareous 
rock.  This  mass  of  pebbles,  held  together  by  calc- 
spar,  is  from  the  cliffs  at  Kemp  Town  ;  and  affords 
a  proof  that  in  periods  very  remote,  the  same  pro- 
cess was  in  action  along  the  Sussex  shores.  These 
beautiful  slabs  of  marble  are  portions  of  stalagmites, 
from  St.  Michael's  Cave,  Gibraltar;  and  this  large 
conical  mass,  which  has  been  cut  through  and 
polished  to  show  its  structure,  was  dug  up  on  the 
summit  of  Alfriston-Hill,  in  Sussex,  and  must  have 


64  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

been  formed  in  some  chalk  cavern,  of  which  no 
traces  now  remain. 

47.  CONSOLIDATION    OF    SAND,    AND    LOOSE 
MATERIALS. — The  changes  effected  by  this  pro- 
cess in  strata  composed  of  loose  materials,  are  of 
still  greater  importance  ;  for  by  an  infiltration  of 
crystallized  carbonate  of  lime,  sand  is  converted 
into  sand-stone, — fragments  of  soft  chalk  are  trans- 
muted into  a  solid  rock,  as  in  the  Coombe-rock  of 
Brighton, — and  accumulations  of  beach,  and  gravel, 
into  a  hard  conglomerate,  as  in  this  example  of  the 
ancient  shingle  bed  of  the  cliffs,  at  Rottingdean, — 
shells,  into  a  building  stone,  as  in  this  mass  from 
Florida, — and  broken  corals,  into  limestone,  as  in 
these  specimens  from  Bermuda.     By  this  agency, 
the  bones  of  animals  become  permeated  with  cal- 
careous spar,  and  the  medullary  cavities  lined  with 
crystals  of  carbonate  of  lime  :  and  clay,  which  has 
cracked  by  drying,  has  its  fissures  filled  up,  and  be- 
comes consolidated  into  those  curious  masses,  called 
septaria,  which  when  polished,  form  the  beautiful 
slabs  for  which  Weymouth  is  so  celebrated. 

48.  DESTRUCTION  OF  ROCKS  BY  CARBONIC  ACID 
GAS. — Although,  in  the  instances  cited  above,  water 
by  its  combination  with  carbonic  acid,  occasions  the 
solidification  of  loose  and  porous  beds  of  detritus, 
yet  the  effect  of  this  gas  on  certain  rocks  is  that  of 
disintegration  ;  for  by  its  solvent  influence  on  the 
felspar,  granite  itself  is  reduced  to  a  friable  state ; 
the  quartz  and  mica,  which  with  felspar  constitute 


§  49.  CARBONIC  ACID  GAS.  65 

granite,  being  set  at  liberty.  The  disintegration  of 
granite,  is  a  striking  feature  throughout  extensive 
districts  in  Auvergne,  especially  in  the  neighbour- 
hood of  Clermont.  In  the  ancient  shingle  of  the 
cliffs  at  Kemp  Town,  near  Brighton,  blocks  of 
granite  occur  which  may  be  crumbled  to  pieces 
between  the  fingers.  I  have  already  shown  you 
masses  of  pebbles  held  together  by  calcareous  spar, 
from  the  same  locality ;  we  have,  therefore,  exam- 
ples in  that  ancient  bed,  both  of  the  conservative 
and  disintegrating  effects  of  carbonic  acid — cement- 
ing the  loose  beach  into  solid  blocks  by  calcareous 
depositions ;  and,  when  in  a  gaseous  state,  or  com- 
bined with  water,  dissolving  the  granite  by  its  action 
on  the  felspar. 

49.  CARBONIC  ACID  GAS  IN  CAVES  AND  WELLS. 
— The  escape  of  carbonic  acid  through  fissures,  into 
mines,  wells,  and  caverns,  is  of  frequent  occurrence ; 
and  as  the  specific  gravity  of  this  gas  is  greater  than 
that  of  atmospheric  air,  it  occupies  the  bottom  of 
these  cavities,  and  its  presence  is  seldom  suspected 
till  shown  by  its  deleterious  effects ;  it  is  called 
choke-damp  by  miners.  Fatal  accidents  often 
happen  to  well-diggers  and  excavators  from  this 
cause., 

The  Grotto  del  Cane,  near  Puzzuoli,  four  leagues 
from  Naples,  has  for  centuries  been  celebrated  on 
account  of  the  carbonic  acid  gas,  containing  in 
combination  much  aqueous  vapour,  which  is  con- 
stantly rising  from  fissures  in  the  rock,  and  is  con- 
F 


66  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

densed  by  the  coldness  of  the  external  atmosphere. 
The  floor  of  the  cavern  being  lower  than  the  en- 
trance, the  gas  is  spread  over  the  bottom  like  a 
pool  of  water,  and  the  upper  part  is  free  from  any 
noxious  vapour.  The  deleterious  effects  of  the 
carbonic  acid  is,  therefore,  not  felt  by  any  creature 
whose  organs  of  respiration  are  above  the  level  of 
this  mephitic  lake ;  but  if  a  dog,  or  other  small 
animal,  enter  the  cave,  it  instantly  falls  senseless, 
and  would  expire  if  not  speedily  removed  :  the 
name  of  the  cave  is  obviously  derived  from  the  ex- 
periment being  often  made  on  dogs,  for  the  amuse- 
ment of  visitors.*  It  is  impossible  to  fire  a  pistol 
at  the  bottom  of  the  cavern ;  for,  although  gun- 
powder may  be  exploded  even  in  carbonic  acid  by 
the  application  of  a  heat  sufficient  to  decompose 
the  nitre,  and  consequently  to  envelope  the  mass  in 
an  atmosphere  of  oxygen  gas,  yet  the  influence  of 
a  mere  spark  from  steel  produces  too  slight  an 
augmentation  of  temperature  for  this  purpose.-)- 

50.  CONSOLIDATION  OF  LOOSE  STRATA  BY  IRON. 
— Water  charged  with  a  large  proportion  of  iron, 
acts  an  important  part  in  the  consolidation  of  loose 
materials,  converting  sand  into  iron-stone,  and  beach 
or  shingle  into  a  ferruginous  conglomerate.  At 
Clapham  Common,  and  other  places  in  the  vicinity 
of  London,  a  very  compact  breccia  occurs  in 
large  blocks,  being  composed  of  chalk-flints,  more 
or  less  broken,  and  rolled,  cemented  together  by 

*  See  Sandys'  Travels.  f  Daubeny  on  Volcanoes. 


§  50.       CONSOLIDATION  OF  LOOSE  STRATA  BY  IRON.         G7 

an  infiltration  of  iron.  In  this  example  of  a 
horse-shoe  firmly  impacted  in  a  mass  of  pebbles 
and  sand,  from  the  sea-beach  at  Eastbourn,  the 
cement  which  binds  the  mass  is  derived  from  the 
iron.  Nails  are  frequently  found  in  the  centre  of 
a  nodule  of  hard  sandstone  formed  by  this  process  ; 
the  nail  having  supplied  the  water  with  the  mate- 
rial by  which  the  surrounding  sand  has  become 
changed  into  stone.  I  have  here  a  cannon  ball 
imbedded  in  the  centre  of  a  nodule  of  iron-stone, 
in  which  are  several  oyster  shells  :  this  specimen 
was  dredged  up  off  the  Sussex  coast,  and  has  evi- 
dently been  consolidated  by  the  solution  of  iron 
afforded  by  the  partial  oxidation  of  the  cannon  ball. 
In  this  very  interesting  mass  of  breccia,*  which  has 
been  produced  by  a  like  process,  are  two  silver 
pennies  of  Edward  I.  This  curious  specimen,  for 
which  I  am  indebted  to  George  Grantham,  Esq.  of 
Barcombe  Place,  Sussex,  was  obtained  from  a  Dutch 
vessel,  which  was  stranded  off  Hastings  a  century 
ago  ;  it  is  a  conglomerate  of  glass  beads,  knives, 

*  This  specimen  was  dug  up  at  a  depth  of  ten  feet  in  the  bed 
of  the  river  Dove,  in  Derbyshire ;  and  the  coins  are  presumed 
to  be  part  of  the  treasures  contained  in  the  military  chest  of  the 
Earl  of  Lancaster,  which  was  lost  in  crossing  the  river  in  the 
dark ;  the  guards  being  alarmed  by  a  sudden  panic,  and  the 
chest  with  all  its  contents  thrown  into  the  Dove.  The  Earl  of 
Lancaster  was  beheaded  in  March  1322  :  the  specimen  was 
discovered  about  six  years  since  ;  more  than  five  centuries  have, 
therefore,  elapsed  since  its  submersion. — See  the  Vignette  of  the 
Title-page,  vol.  i. 

F2 


68  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

and  sand;  the  cementing  material  having  been 
derived  from  the  oxidation  of  the  blades.  In 
the  bed  of  the  Thames,  large  masses  of  a  ferru- 
ginous conglomerate  are  occasionally  found,  in 
which  Roman  coins,  and  fragments  of  pottery,  are 
imbedded ;  the  stone  being  formed  of  sand  and  clay 
impregnated  and  consolidated  by  ferruginous  infil- 
tration. 

These  specimens  of  oxide  of  iron  were  dug  up  in  a 
marshy  soil,  near  Bolney,  in  Sussex,  and  are  of  the 
same  nature  as  the  substance  called  bog-iron  ore, 
which  so  frequently  occurs  in  peat.  The  ebony 
colour  of  the  woods  from  Ireland,  which  we  have 
already  examined,  has  been  derived  from  an  im- 
pregnation of  iron.  Specimens  of  bog-iron  are  not 
uncommon  in  the  superficial  loam  and  gravel  of 
the  south-east  of  England. 

The  consolidation  of  sand  and  other  loose  mate- 
rials by  these  agencies,  is  taking  place  everywhere ; 
on  the  shores  of  the  Mediterranean ;  on  the  coasts 
of  the  West  India  Islands,  and  of  the  Isle  of  Ascen- 
sion ;  and  on  the  borders  of  the  United  States ;  thus 
the  remains  of  man,  at  Guadaloupe  —  of  turtles, 
in  the  Isle  of  Ascension  —  of  recent  shells,  and 
bones  of  ruminants,  at  Nice — of  ancient  pottery  in 
Greece — and  of  animal  and  vegetable  substances. 
in  our  own  country,  have  become  imbedded  and 
preserved. 

I  now  proceed  to  notice  a  few  instances  of  these 
interesting  and  important  operations,  by  which 


§51.  MARINE  LIMESTONE.  69 

much  of  the  solid  crust  of  the  globe  is  continually 
being  renewed. 

51.  RECENT  FORMATION  OF  MARINE  LIMESTONE 
IN  THE  BERMUDAS. — The  valuable  series  of  speci- 
mens before  me  (presented  by  W.  D.  Saull,  Esq.) 
is  from  the  Bermuda  Islands,  and  affords  examples 
of  this  class  of  deposits  in  different  states  of  con- 
solidation. The  sea  which  surrounds  the  Bermudas 
abounds  in  corals  and  shells ;  and  from  the  action 
of  the  waves  on  the  reefs,  and  on  the  dead  shells, 
the  water  becomes  loaded  with  calcareous  matter. 
Much  of  this  detritus  is,  no  doubt,  carried  down  to 
the  profound  depths  of  the  ocean,  and  there  en- 
velopes the  remains  of  animals  and  vegetables,  thus 
forming  new  strata  for  the  use  of  future  ages ;  but 
a  great  proportion  is  borne  by  the  waves  towards 
the  shores,  and  deposited  in  the  state  of  fine  sand. 
This  sand  is  drifted  inland  by  the  winds,  and  be- 
comes more  or  less  consolidated  by  the  percolation 
of  water,  and  the  infiltration  of  crystallized  car- 
bonate of  lime ;  a  fine  white  calcareous  stone  is  thus 
formed,  which  in  some  localities  is  sufficiently  com- 
pact for  building.  Imbedded  in  this  limestone  are 
numerous  shells  and  corals,  of  the  species  which 
inhabit  the  neighbouring  seas :  in  some  instances 
the  large  mottled  trochus,  so  well  known  to  col- 
lectors both  in  its  natural  and  polished  state,  with 
all  its  colours  preserved,  is  imbedded  in  a  pure, 
white  limestone ;  in  many  specimens  the  colours 
are  faded,  and  the  shells  very  much  in  the  state  of 


70  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

those  found  in  the  tertiary  strata  at  Grignon — in 
others  the  shelly  matter  is  wanting,  but  the  hard 
limestone  retains  the  forms  and  markings  of  the 
originals.  The  corals  are  imbedded  in  a  similar 
manner ;  and  masses  occur  in  the  limestone  so  like 
the  fossil  corals  of  the  oolite  of  this  country,  that  it 
requires  an  experienced  eye  to  detect  their  real 
nature. 

In  a  suite  of  specimens,  showing  the  transition 
from  loose  sand  to  a  solid  rock,  we  have — 

1.  Broken  shells  and  corals,  retaining  their  colours. 

2.  Similar  materials,  more  comminuted  and  com- 
pletely bleached. 

3.  An  aggregation  of  fine  sand,  broken  shells, 
and  corals. 

4.  Coarse  friable  limestone,  resembling  soft  chalk, 
and  composed  of  comminuted  corals,  &c. 

5.  Hard  limestone,  of  similar  materials. 

6.  Compact  limestone,  enveloping  shells  and  peb- 
bles. 

7.  A  fine  indurated  limestone,  so  hard  as  to  be 
with  difficulty  broken  by  the  hammer,  inclosing 
a  few  shells,  and  corals  :  this  stone  is  employed 
for  building. 

Mr.  Lyell  has  described  a  fresh-water  limestone, 
containing  recent  shells  and  aquatic  plants,  which 
is  in  the  progress  of  formation  in  the  lakes  of  For- 
farshire,  in  Scotland.*  In  the  specimens  before  us, 
which  were  collected  by  Mr.  Lyell,  are  various 
*  Geological  Transactions,  vol.  i.  p.  73,  new  series  » 


§52.  FOSSIL  HUMAN  SKELETONS.  71 

species  of  fresh-water  shells,  and  masses  of  that 
common  lacustrine  plant,  the  Ckara  medicaginula, 
beautifully  preserved  ;  even  the  minute  seed-vessels 
of  the  chara  are  found  converted  into  stone,  in  pre- 
cisely the  same  manner  as  those  which  occur  in  the 
ancient  fresh-water  tertiary  limestones.  Here  then 
is  an  example  of  the  formation  of  a  modern  lacus- 
trine rock ;  while,  in  the  deposits  at  Bermuda,  we 
have  proof  that  the  sea  is,  at  this  time,  producing 
effects  analogous  to  those  which  have  given  rise  to 
many  of  the  ancient  secondary  strata. 

52.  FOSSIL  HUMAN  SKELETONS  OF  GUADALOUPE. 

— Similar  formations  are  in  progress  along  the  shores 
of  the  whole  West  Indian  Archipelago  ;  and  in  St. 
Domingo  they  have  greatly  extended  the  plain  of 
Cayes,  where  accumulations  of  conglomerates  occur, 
and  in  which,  at  the  depth  of  twenty  feet,  fragments 
of  ancient  pottery  have  been  discovered. 


A  B 

TAB.  9.— PLAN  OF  THE  CLIFFS  AT  GUADALOUPE. 

A,  Ancitnt  rocks;   B,  recent  limestone,  in  which  human  skeletons  are 
found  imbedded. 

On  the  north-east  coast  of  the  main  land  of  Gua- 


72  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

daloupe,  a  bed  of  recent  limestone  forms  a  sloping 
bank,  or  glacis,  from  the  steep  cliffs  of  the  island 
to  the  sea,  and  is  nearly  all  submerged  at  high 
tides.  This  modern  rock  is  composed  of  conso- 
lidated sand,  and  comminuted  shells  and  corals,  of 
species  now  inhabiting  the  adjacent  seas.  Land 
shells,  fragments  of  pottery,  stone  arrow-heads, 
carved  stone  and  wooden  ornaments,  and  human 
skeletons,  are  found  therein  imbedded.  This  being 
the  only  known  undoubted  instance  of  the  occur- 
rence of  human  bones  in  solid  limestone,  has  excited 
great  attention  ;  and  the  fact,  simple  and  self-evi- 
dent as  is  its  history,  has  been  made  the  foundation 
of  many  vague  and  absurd  hypotheses. 

In  most  instances  the  bones  are  dispersed  ;  but  a 
large  slab  of  rock,  in  which  a  considerable  portion  of 
the  skeleton  of  a  female  is  imbedded,  is  preserved 
in  the  British  Museum,  and  has  been  described  by 
Mr.  Konig,  in  a  highly  interesting  memoir  in  the 
Philosophical  Transactions,  of  1814. 

The  annexed  representation  (TAB.  10.)  will  serve 
to  convey  an  idea  of  this  celebrated  relic,  which 
was  detached  from  the  rock  at  the  Mole,  near 
Point-a-Pitre. 

-  In  this  specimen  the  skull  is  wanting,  but  the 
spinal  column,  many  of  the  ribs,  the  bones  of  the 
left  arm  and  hand,  of  the  pelvis,  and  of  the  thighs 
and  legs,  remain.  The  bones  still  contain  some 
animal  matter,  and  the  whole  of  their  phosphate 
of  lime.  It  is  remarkable,  that  the  fragments 


§52. 


FOSSIL  HUMAN  SKELETONS. 


73 


of  the  skull  of  this  very  specimen  have  recently 
been  purchased  for  the  museum  at  South  Carolina, 


TAB.  10. — FOSSIL  HUMAN  SKELETON,  FROM  GUADALOUPE. 
In  the  British  Museum;  size  of  the  original,  4  feet  2  inches  by  2  feet. 

of  a  French  naturalist,  who  brought  them  from 
Guadaloupe ;  and  they  have  been  described  by  Pro- 
fessor Moultrie,  of  the  Medical  College  of  that 
State.  These  relics  consist  of  portions  of  the 
temporal,  parietal,  frontal,  sphenoidal,  and  inferior 
maxillary  bones,  of  the  right  side  of  the  skull.  An 
entire  skeleton  was  also  discovered  in  the  usual 
position  of  burial ;  another,  which  was  in  a  softer 
sandstone,  was  in  a  sitting  posture.  The  bodies, 


74  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

thus  differently  situated,  may  have  belonged  to 
distinct  tribes.  General  Ernouf,  who  carefully 
investigated  this  interesting  deposit,  conjectured 
that  the  presence  of  the  bones  might  be  explained 
by  the  circumstance  of  a  battle,  and  the  massacre 
of  a  tribe  of  Gallibis  by  the  Caribs,  having  taken 
place  near  this  spot,  about  120  years  ago,  and  the 
bodies  of  the  slain  been  interred  on  the  shore; 
the  skeletons  having  subsequently  been  covered  by 
sand-drift,  which  has  been  converted  into  lime- 
stone. Dr.  Moultrie,  however,  from  a  rigorous 
examination,  and  comparison  of  the  bones  of  the 
skull  in  his  possession,  is  of  opinion,  that  the 
specimen  in  the  British  Museum  did  not  belong 
to  an  individual  of  the  Carib,  but  to  one  of  the 
Peruvian  race,  or  of  a  tribe  possessing  a  similar 
craniological  development. 

In  another  skeleton  from  Guadaloupe,  now  in 
the  museum  of  the  Jar  din  des  Plantes,  and  repre- 
sented in  the  last  edition  of  Cuvier's  Theorie  de  la 
Terre,  the  figure  is  bent,  the  spine  forms  an  arc, 
and  the  thighs  are  drawn  up  as  if  the  individual 
were  in  a  sitting  posture ;  a  portion  of  the  upper 
jaw,  and  the  left  half  of  the  lower,  with  several 
teeth,  nearly  the  whole  of  one  side  of  the  trunk 
and  pelvis,  and  a  considerable  portion  of  the  upper 
and  lower  left  extremities,  are  preserved  (TAB.  11). 
The  stone  is  a  travertine  (page  58),  and  incloses 
terrestrial  and  marine  shells ;  it  is  evident  that  the 
former  have  be,en  drifted  by  streams  from  the  in- 


§53. 


IMPRESSIONS  OF  HUMAN  FEET. 


terior,  and  the  latter  deposited  by  the  ocean.  In 
the  bed  from  which  this  block  was  extracted,  were 
found  teeth  of  the  caiman  (a  species  of  crocodile), 


TAB.  11. — HUMAN  SKELETON  FROM  GUADALOUPE. 
In  the  Museum  at  Paris. 

stone  hatchets,  and  a  piece  of  wood,  having  rudely 
sculptured  on  one  side  a  mask,  and  on  the  other 
the  figure  of  an  enormous  frog :  it  is  of  guaiacum, 
but  has  become  extremely  hard,  and  as  black 
as  jet. 

53.  IMPRESSIONS  OF  HUMAN  FEET  IN  SAND- 
STONE. —  In  connexion  with  the  occurrence  of 
human  bones  in  limestone,  I  will  here  notice  a 
discovery  of  the  highest  interest,  but  which  has  not, 


76  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

as  yet,  excited  among  scientific  observers  the  atten- 
tion which  its  importance  demands.  I  allude  to  the 
fact  announced  in  the  American  Journal  of  Science, 
(vol.  v.  for  1822,)  of  impressions  of  human  feet  in 
sandstone,  discovered  many  years  ago  in  a  quarry 
at  St.  Louis,  on  the  western  bank  of  the  Mississippi. 


TAB.  12.— IMPRESSIONS  OF  HUMAN  FEET  IN  SANDSTONE. 

The  above  figure  is  an  exact  copy  of  the  original 
drawing,  and  exhibits  the  impressions  of  the  soles 
of  two  corresponding  human  feet,  placed  at  a  short 
distance  from  each  other,  as  of  an  individual  standing 
upright,  in  an  easy  position.  The  prints  are  de- 
scribed as  presenting  the  perfect  impress  of  the  feet 
and  toes,  exhibiting  the  form  of  the  muscles,  and 
the  flexures  of  the  skin,  as  if  an  accurate  cast  had 
been  taken  in  a  soft  substance.  They  were  at  first 
supposed  to  have  been  cut  in  the  stone  by  the  native 


§  54.  ISLE  OF  ASCENSION.  77 

Indians,  but  a  little  reflection  sufficed  to  show  that 
they  were  beyond  the  efforts  of  those  rude  children 
of  nature ;  since  they  evinced  a  skill,  and  fidelity  of 
execution,  which  even  my  distinguished  friend,  Sir 
Francis  Chantrey,  could  not  have  surpassed.  No 
doubt  exists  in  my  mind,  that  these  are  the  actual 
prints  of  human  feet  in  soft  sand,  which  was  quickly 
converted  into  solid  rock  by  the  infiltration  of  cal- 
careous matter,  in  the  manner  already  described. 
The  length  of  each  foot  is  ten  inches  and  a  half,  the 
spread  of  the  toes  four  inches,  indicating  the  usual 
stature;  and  the  nature  of  the  impression  shows 
that  the  feet  were  unconfined  by  shoes  or  sandals. 
This  phenomenon,  unique  of  its  kind,  is  fraught 
with  so  much  importance,  that  I  have  requested 
Professor  Silliman  to  ascertain  the  nature  of  the 
sandstone,  and  the  period  of  its  formation.  Here- 
after I  shall  have  to  direct  your  attention  to  im- 
pressions of  another  kind,  in  rocks  of  immense 
geological  antiquity. 

54?.  ISLE  OF  ASCENSION. — This  island,  which  is 
a  volcanic  cone  in  the  midst  of  the  Atlantic,  appears 
to  have  been  a  dome  of  trachytic  rocks,  subse- 
quently affording  vent  to  lava  currents ;  and  its 
shores  are  bounded  by  a  conglomerate  formed  of 
sand  with  comminuted  shells,  corals,  echini,  and  frag- 
ments of  lava.  In  the  suite  of  specimens  before  us 
are  portions  of  this  conglomerate  in  various  states 
of  consolidation.  They  are  composed  of  corals, 
which  still  retain  their  colour ;  of  shells,  more  or 


78  THE  WONDERS  OF  GEOLOGY.  LECT.  1. 

less  broken ;  and  of  ^and  of  similar  materials ; 
they  also  contain  pebbles  of  trachytic  and  glassy 
lava.  The  shores  of  this  island  are  a  favourite 
resort  of  turtles,  which  repair  thither  in  immense 
numbers,  and  deposit  their  eggs  in  the  loose  sand  : 
the  rapid  conversion  of  the  coarse,  calcareous  banks 
into  solid  stone,  occasions  the  frequent  imbedding, 
and  preservation  of  the  eggs ;  and  there  are  speci- 
mens in  the  cabinet  of  the  Geological  Society,  in 
which  the  bones  of  young  turtles,  just  on  the  point 
of  being  hatched,  are  well  preserved.*  The  con- 
glomerate of  the  Isle  of  Ascension  is,  as  you  may 
observe,  principally  composed  of  corals.  Here  we 
have  another  example  of  a  rock  formed  of  the  calca- 
reous skeletons  of  those  wonderful  forms  of  organic 
existence.  It  is  not  my  intention  in  this  place  to 
dwell  on  the  geological  changes  produced  by  recent 
zoophytes,  in  the  formation  of  coral  reefs,  &c.,  as 
the  examination  of  the  recent,  and  fossil  corals,  will 
form  the  subject  of  a  subsequent  lecture. 

55.  DRIFTED  SAND. — We  have  already  briefly 
alluded  to  the  encroachments  on  the  land  by  the 
drifting  of  sand-banks,  thrown  up  beyond  the  reach 
of  the  tide,  and  driven  by  the  winds  inland ;  thus 
effecting  the  desolation  of  whole  regions  by  their 
slow,  but  certain  progress.  Egypt  instantly  presents 
herself  to  the  imagination,  with  her  stupendous 
pyramids,  the  sepulchres  of  a  mighty  race  of  mon- 
archs,  and  the  wonder  of  the  world — her  temples, 
*  See  LyelFs  Principles  of  Geology,  5th  edit.  vol.  iii.  p.  269. 


§  55.  DRIFTED  SAND.  79 

and  palaces,  once  so  splendid  and  massive,  as  to 
bid  defiance  to  the  ravages  of  time  —  her  plains, 
and  valleys,  formerly  teeming  with  abundance,  and 
supporting  a  numerous  population  —  now  stripped 
of  her  ancient  glories,  her  fairest  regions  depopu- 
lated, and  converted  into  arid  wastes, — her  cities 
overwhelmed,  and  prostrate  in  the  dust — and  the 
colossal  monuments  of  her  kings,  and  the  temples 
of  her  gods,  half  buried  beneath  the  sands  of  the 
Desert !  The  drifting  of  the  sands  of  the  Lybian 
desert  by  the  westerly  winds,  observes  M.  De  Luc, 
has  left  no  lands  capable  of  cultivation  on  those 
parts  of  the  western  bank  of  the  Nile  which  are  not 
sheltered  by  mountains ;  while  in  Upper  Egypt, 
whole  districts  are  covered  by  moveable  sands,  and 
here  and  there  may  be  seen  the  summits  of  temples, 
and  the  ruins  of  cities  which  they  have  overwhelmed. 
"  Nothing  can  be  more  melancholy,"  says  Denon, 
"  than  to  walk  over  villages  swallowed  up  by  the 
sand  of  the  Desert,  to  trample  under  foot  their 
roofs  and  minarets,  and  to  reflect  that  yonder  were 
cultivated  fields,  that  there. grew  trees,  that  here 
were  the  dwellings  of  men,  and  that  all  have  now 
vanished.  The  sands  of  the  Desert  were  in  ancient 
times  remote  from  Egypt ;  and  the  Oases  which 
still  appear  in  the  midst  of  this  sterile  region,  are 
the  remains  of  fertile  soils  which  formerly  extended 
to  the  Nile."* 

*  See  an  Essay,  on  the  Moving  Sands  of  Africa,  in  Professor 
Jamieson's  Translation  of  Cuvier's  Theory  of  the  Earth,  p.  375. 

Mr. 


80  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

56.  SAND-FLOOD,  A.-TD  RECENT  LIMESTONE  OF 
CORNWALL. — On  many  parts  of  the  shores  of  Scot- 
land, sand-floods  have  converted  tracts  of  great 
fertility  into  barren  wastes :  and  on  the  northern 
coast  of  Cornwall  an  extensive  district  has  been 
covered  by  drifted  sand,  which  has  become  con- 
solidated by  the  percolation  of  water  holding  iron  in 
solution,  and  in  some  places  forms  ranges  of  low 
mounds,  and  hills,  forty  feet  high.  This  sandstone 
offers  a  striking  and  most  interesting  example  of 
recent  formation,  and  has  been  described  by  Dr. 
Paris,  in  a  memoir  which  I  do  not  hesitate  to  cha- 
racterize as  one  of  the  most  graphic,  and  instructive 
geological  essays  on  modern  deposits,  that  has  ap- 
peared in  this  country.*  The  sand  has  evidently 
been  drifted  from  the  sea  by  hurricanes,  probably  at 
a  very  remote  period ;  it  is  first  seen  in  a  slight,  but 
increasing  state  of  aggregation,  on  several  parts  of 
the  shore  in  the  Bay  of  St.  Ives.  Around  the  pro- 
montory of  New  Kaye,  the  sandstone  occurs  in 
various  states  of  induration,  from  that  of  a  friable 
aggregate,  to  a  stone  so  compact,  as  to  be  broken 

Mr.  Wilkinson,  in  a  late  highly  interesting  work,  questions  the 
correctness  of  these  inferences,  as  to  the  extent  of  the  sand- 
floods,  and  asserts,  that  at  the  present  time  the  alluvial  soil 
on  the  increase,  the  deposits  from  the  inundations  of  the  Nile 
more  than  counterbalancing  the  inroads  of  the  sands  ;  and  that 
the  land  now  capable  of  cultivation  in  the  valley  of  Egypt  is 
greater  than  at  the  time  of  the  Pharaohs. — Manners  and  Customs 
of  the  Ancient  Egyptians,  vol.  i.  pp.  218 — 222. 
*  Appendix  E. 


§57.  SILICIOUS  DEPOSITIONS.  81 

with  difficulty  by  the  hammer ;  and  which  is  used 
in  the  construction  of  churches  and  houses.  Upon 
examining  the  stone  with  a  lens,  it  appears  to  be 
principally  made  up  of  comminuted  shells ;  and  it 
is  worthy  of  remark,  that  the  shelly  particles  are 
frequently  found  to  be  spherical,  from  the  previous 
operation  of  water,  and  some  portions  of  the  rock 
closely  resemble  the  ancient  limestone  called  oolite, 
which  will  hereafter  come  under  our  notice.  The 
rocks  upon  which  the  sandstone  reposes  are  clay, 
slate,  and  slaty  limestone ;  and  the  water  effecting 
their  decomposition  may  have  thus  obtained  the 
iron,  alumina,  and  other  mineral  matters  by  which 
the  loose  sand  has  been  converted  into  sand- 
stone. 

The  infiltration  of  water  thus  impregnated,  Dr. 
Paris  observes,  is  a  common  and  extensive  cause  of 
lapidificatiori :  at  Pendean  cove,  granitic  sand  is 
gradually  hardening  into  breccia,  by  this  process ; 
and  in  the  island  of  St.  Mary,  is  becoming  indu- 
rated by  the  slow  action  of  water  impregnated  with 
iron. 

57.  SILICIOUS  DEPOSITIONS. — Silicious  earth, 
or  the  earth  of  flint,  is  another  abundant  mineral, 
and  constitutes  so  large  a  proportion  of  the  rocks 
and  strata,  that  it  is  computed  to  form,  either  in  a 
pure  or  combined  state,  nearly  one-half  of  the 
solid  crust  of  the  globe.  The  flints  from  our 
cliffs,  the  boulders  and  gravel  on  our  shores,  and 
the  pebbles  of  agate,  quartz,  and  chalcedony,  are 


82  THE  WONDERS  OF  GEOLOGY.  LECT.  i. 

well-known   examples   of   the   usual   varieties   of 
silex.* 

I  scarcely  need  observe,  that  this  nodule  of  flint, 
obtained  from  a  neighbouring  chalk  quarry,  has 
once  been  in  a  soft  or  fluid  state  ;  for  here  we  per- 
ceive impressions  of  shells,  and  of  the  spines  of  an 
echinus  deeply  imprinted  on  its  surface.-)-  We  have 
already  seen  that  water  impregnated  with  carbonic 
acid  gas  is  capable  of  holding  lime  in  solution ;  and 
that  travertine,  limestone,  and  other  calcareous 
deposits,  have  originated  from  this  agency ;  and 
although,  even  in  the  present  advanced  state  of 
chemical  knowledge,  we  are  unacquainted  with  the 

*  Here  I  would  digress  for  a  few  moments,  to  notice  an 
opinion  which  is  so  generally  prevalent,  that  I  may  be  permitted 
to  assume,  that  even  some  of  my  readers  may  not  be  prepared 
at  once  to  answer  the  question, — Do  stones  grow  ?  The  farmer 
who  annually  ploughs  the  same  land,  and  every  year  observes  a 
fresh  CROP  of  stones,  would  probably  answer  in  the  affirmative ; 
and  the  general  observer,  who  had  for  successive  years  noticed 
his  gardens  and  plantations  strewed  with  stones,  notwithstanding 
their  almost  daily  removal,  might  entertain  the  same  opinion. 
A  moment's  reflection,  however,  will  serve  to  show,  that  it  is 
impossible  stones  can  be  said  to  grow,  in  the  proper  acceptation 
of  the  term.  Organic  bodies  grow,  because  they  are  provided 
with  vessels  by  which  they  are  capable  of  taking  up  and  assimi- 
lating particles  of  matter,  and  converting  them  into  their  own 
substance ;  but  an  inorganic  body  can  only  increase  in  bulk  by 
the  addition  of  extraneous  matter  to  its  outer  surface ;  hence 
stones  may  be  incrusted,  or  they  may  become  conglomerated 
together,  but  they  cannot  grow. 

f  Vide  "  Thoughts  on  a  Pebble  ;  or,  a  First  Lesson  in  Geo- 
logy." Fifth  edition;  1837. 


§  53.  THE  GEYSERS.  83 

process  by  which  any  large  proportion  of  flint  can 
be  held  in  solution  by  water,  yet  we  have  unques- 
tionable proofs,  that  the  solution  of  silicious  earth 
has  been  effected  by  natural  processes,  on  a  very 
extensive  scale.  At  the  present  moment,  Nature, 
in  her  secret  laboratories,  is  still  carrying  on  a 
modification  of  the  same  process ;  and  of  this  fact 
we  have  a  remarkable  instance  in  the  Geysers  of 
Iceland,  and  in  the  springs  of  Carlsbad,  in  Bohemia. 
Professor  Silliman  remarks,  that  "  the  sulphuret  of 
silicon,  which  is  the  base  of  silex,  is  very  soluble, 
and  that  silicious  earth  itself  is  taken  up  by  fixed 
alkalies,  and  by  fluoric  acid ;  and  that  these  agencies, 
like  most  of  those  which  are  chemical,  are  rendered 
more  active  by  heat."  A  high  temperature  there- 
fore appears  necessary  to  enable  water  to  dissolve 
a  large  proportion  of  silex,  &c. ;  hence,  we  find  that 
the  thermal  springs  of  volcanic  regions  are  the 
principal  agents  by  which  silicious  depositions  and 
incrustations,  are  at  present  produced. 

58.  THE  GEYSERS. — The  Geysers,  or  boiling 
fountains,  of  Iceland,  have  long  been  celebrated  for 
possessing  this  property  in  an  extraordinary  degree  ; 
holding  a  large  proportion  of  silex  in  solution,  and 
depositing  it,  when  cooling,  on  vegetables  and  other 
substances,  in  a  manner  similar  to  that  in  which 
carbonate  of  lime  is  precipitated  by  the  incrusting 
springs  of  which  we  have  already  spoken.  Iceland 
may  be  considered  as  a  mass  of  volcanic  matter ; 
the  only  substances  not  of  volcanic  origin  in  the 


84  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

whole  island,  being  beds  of  surturbrand,  or  bitu- 
minous wood,  in  which  occur  leaves,  trunks,  and 
branches  of  trees,  with  clay  and  ferruginous  earth. 
These  strata  support  alternating  beds  of  basalt, 
tufa,  and  lava,  which  form  the  summit  of  the  hill  in 
which  the  vegetable  remains  occur.  The  Geysers, 
of  which  there  are  a  considerable  number,  are 
springs,  or  rather  intermittent  fountains  of  hot 
water,  which  issue  from  crevices  in  the  lava.  A 
fountain  of  boiling  water,  accompanied  with  a  great 
evolution  of  vapour,  first  appears,  and  is  ejected  to  a 
considerable  height ;  a  volume  of  steam  succeeds, 
and  is  thrown  up  with  great  force,  and  a  terrific 
noise  like  that  produced  by  the  escape  of  steam 
from  the  boiler  of  an  engine.  This  operation  con- 
tinues sometimes  for  more  than  an  hour ;  an  interval 
of  repose  of  uncertain  duration  succeeds,  after  which 
the  same  phenomena  are  repeated.  If  stones  are 
thrown  into  the  mouth  of  the  cavity,  from  which 
the  fountain  has  issued,  they  are  ejected  with  vio- 
lence, after  a  short  interval,  and  again  jets  of  boiling 
water,  vapour,  and  steam  appear  in  succession. 
The  eruptions  of  the  "  great  Geyser,"  witnessed  by 
Sir  G.  S.  Mackenzie,*  were  preceded  by  a  sound  like 
the  distant  discharge  of  heavy  ordnance,  and  the 
ground  shook  sensibly  ;  the  sound  was  rapidly  re- 
peated, when  the  water  in  the  basin,  after  heaving 
several  times,  suddenly  rose  in  a  large  column, 

*  Travels  in  Iceland,  in  the  summer  of  the  year  1810,  by 
Sir  George  Steuart  Mackenzie,  Bart. 


§58. 


THE  GEYSERS. 


85 


accompanied  by  clouds  of  steam,  to  the  height  of 
ten  or  twelve  feet.  The  column  seemed  to  burst, 
and  sinking  down,  produced  a  wave,  which  caused 
the  water  to  overflow  the  basin.  A  succession  of 


TAB.  13.— PLAN  OF  THE  GEYSERS. 

eighteen  or  twenty  jets  now  took  place,  some  of 
which  rose  to  a  height  of  fifty  or  sixty  feet.  After 
the  last  eruption,  which  was  the  most  violent,  the 


86  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

water  suddenly  left  the  basin,  and  sunk  into  the 
pipe  in  the  centre  to  a  depth  of  ten  feet.  After  a 
few  hours  the  eruption  was  repeated  ;  the  jets  some- 
times attaining  ninety  feet  in  altitude.  The  basin 
of  the  "  great  Geyser"  is  an  irregular  oval,  about 
fifty-six  feet  by  forty- six,  formed  of  a  mound  of 
silicious  depositions  about  seven  feet  high ;  the  pipe 
through  which  the  water  is  ejected  being  sixteen 
feet  in  diameter  at  the  opening,  but  contracting  to 
ten  feet  lower  down  ;  its  perpendicular  depth  is 
estimated  at  sixty  feet.  Sir  G.  S.  Mackenzie  has 
proposed  an  ingenious  explanation  of  these  pheno- 
mena, which  the  diagram  in  the  preceding  page  will 
serve  to  illustrate.  It  is  supposed  that  the  water 
from  the  surface  percolates  through  crevices  (Tab. 
13,  a)  into  a  cavity  in  the  rock  (£>),  and  heated 
steam,  produced  by  volcanic  agency,  rises  through 
fissures  in  the  lava  (cc).  The  steam  becomes  in 
part  condensed,  and  the  water  filling  the  lower  part 
of  the  cavity  (d)  is  raised  to  a  boiling  temperature, 
while  steam  under  high  pressure  occupies  the  upper 
part  of  the  chasm.  The  expansive  force  of  the 
steam  becomes  gradually  augmented,  till  at  length 
the  water  is  driven  up  the  fissure  or  pipe  (e),  and  a 
boiling  fountain  with  an  escape  of  vapour  is  pro- 
duced, which  continues  playing  till  all  the  water 
in  the  reservoir  is  expended,  and  the  steam  itself 
escapes  with  great  violence  till  the  supply  is  ex- 
hausted.* 

*  Travels  in  Iceland,  p.  229. 


§  58.  THE  GEYSERS.  87 

The  silicious  concretions  formed  by  these  springs 
cover  an  extent  of  four  leagues ;  these  are  speci- 
mens of  the  more  friable  varieties,  presented  me  by 
Professor  Babbage.  M.  Eugene  Robert,  who  has 
recently  visited  Iceland,  states  that  this  curious 
formation  may  be  seen,  passing  by  insensible  grada- 
tions, from  a  loose  friable  state,  the  result  of  a  rapid 
deposition,  to  the  most  compact  and  transparent 
masses,  in  which  impressions  of  the  leaves  of  the 
birch-tree,  and  portions  of  the  stems,  are  distinctly 
perceptible,  presenting  the  appearance  of  the  aga- 
tized  woods  of  the  West  Indies.  Rushes,  and  vari- 
ous kinds  of  mosses  converted  into  a  white  silicious 
rock,  in  which  the  minutest  fibres  are  preserved, 
also  occur ;  but  on  the  margin  of  the  Geysers,  from 
the  splashing  of  the  water,  the  depositions  resemble 
large  cauliflowers ;  and  on  breaking  these  masses, 
vegetable  impressions  are  often  discovered.  Nume- 
rous thermal  springs  occupy  the  valley  in  the  interior 
of  the  island,  in  the  midst  of  which  the  Geysers  are 
situated.  It  is  evident  that  these  waters  arise  from 
deep  crevices,  in  which  they  have  been  heated  by 
volcanic  fires.  The  rivers  proceeding  from  the 
springs  often  resemble  milk  in  appearance,  owing 
to  the  argillaceous  bole  which  they  take  up  in  their 
passage  among  the  silicious  concretions  :  such  are 
the  white  rivers  of  Olassai.  Mount  Hecla,  like  all 
the  mountains  of  Iceland,  is  entirely  covered  with 
snow,  and  no  smoke  appears  on  its  summit.  Accu- 
mulations of  rolled  masses  of  obsidian  and  pumice- 


88  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

stone  form  a  layer  on  the  flanks  of  the  mountain, 
thirty  feet  thick ;  stems  and  branches  of  the  birch- 
tree  occur  in  the  midst  of  this  bed ;  they  are  the 
remains  of  the  ancient  forests  of  the  island,  which 
the  volcanic  eruptions  have  entirely  extirpated.* 

This  modern  silicious  formation  is  a  fact  of  great 
interest  and  importance.  It  tells  us  in  language 
that  cannot  be  mistaken,  that  the  most  insoluble 
and  refractory  substances  may  be  reduced  to  a 
liquid  state,  and  again  become  consolidated,  and 
assume  other  modifications,  merely  by  the  agency 
of  thermal  waters  ;  hence  the  envelopement  of  the 
delicate  corals,  shells,  &c.  which  are  so  abundant  in 
flint  nodules,  is  readily  explained. 

59.  HERTFORDSHIRE  CONGLOMERATE,  OR  PUD.- 
DING-STONE. — We  have  before  us  a  collection  of 
conglomerates  formed  by  carbonate  of  lime;  in 
other  words,  aggregations  of  pebbles,  sand,  shells, 
and  corals,  which  are  cemented  together  by  calca- 
reous spar  and  by  ferruginous  solutions  :  but  this 
specimen  is  an  example  of  a  mass  of  rounded  flint 
pebbles,  imbedded  in  a  silicious  paste,  forming  the 
well-known  substance  called  Hertfordshire  pudding- 
stone,  which  was  formerly  in  much  request ;  for  the 
cement,  being  as  hard  and  solid  as  the  pebbles  them- 
selves, the  stones  admit  of  being  cut  and  polished 
by  the  lapidary  into  a  great  diversity  of  ornaments. 
The  formation  of  this  rock  must  have  been  effected 
by  a  stream  of  silicious  matter  flowing  into  a  bed 
*  Bulletin  de  la  Societe  Geologique  de  France. 


§  60.  EFFECTS  OF  HIGH  TEMPERATURE.  89 

of  gravel,  and  converting  some  portions  of  the  loose 
pebbles  into  a  solid  mass,  while  those  parts  which 
the  liquid  flint  did  not  reach  remained  in  the  state 
of  loose  water- worn  materials.  It  is  not  my  inten- 
tion in  this  lecture  to  dwell  on  the  silicification  *  of 
the  remains  of  animals  and  plants  ;  it  will  suffice  to 
remark,  that  in  the  silicified  woods  from  the  West 
Indies  the  most  minute  vegetable  structure  may  be 
detected,  although  the  specimens  will  strike  fire 
with  steel. 

60.  EFFECTS  OF  HIGH  TEMPERATURE.  —  The 
phenomena  presented  to  our  notice  in  this  investiga- 
tion of  the  Geysers  of  Iceland,  lead  to  the  conside- 
ration of  another  agent  in  the  transmutations  that 
take  place  in  the  crust  of  the  globe.  It  must  be 
obvious  to  every  intelligent  mind,  that  beds  of  un- 
connected and  porous  materials  can  have  acquired 
hardness  and  solidity  only  by  one  of  the  following 
processes,  namely  : — 1st,  by  matter  dissolved  in  a 
fluid,  and  afterwards  deposited  among  the  porous 
masses  in  the  manner  just  described ;  or,  2dly,  by 
the  reduction  of  the  materials  by  heat  into  a  state 
of  softness  or  fusion,  and  their  subsequent  conver- 
sion, by  cooling,  into  a  solid  mass.-)-  Fire — or  to 
speak  more  correctly,  a  high  temperature,  however 
induced,  whether  by  electro-magnetic  influence,  or 
proceeding  from  central  or  medial  sources  of  heat — 
and  water,  are  therefore  the  great  agents  by  which 
the  mineral  masses  composing  the  crust  of  our 
*  Petrifaction  by  flint.  f  Playfair. 


90  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

planet  have  been  and  are  still  being  modified.     We 
have  already  seen  how  vast  are  the  changes  which 
result  from  the  effects  of  water  ;  we  must  now  take 
a  rapid  survey  of  the  influence  which  caloric  is 
capable  of  exerting ;  an  influence  far  more  universal 
and  varied  than  we  may  at  first  be  prepared  to  ex- 
pect.    The  expansive  power  which  heat  exerts  on 
most  substances,   and  its  conversion  of  the  most 
solid  and  durable  bodies,  first  into  a  fluid,  and  lastly 
into  a  gaseous  state,  are  phenomena  so  familiar  as 
to  require  no  lengthened  comment.    But  the  effects 
of  heat  are  found  to  vary  according  to  the  circum- 
stances under  which  bodies  are  submitted  to  its 
operation,  and  hence  the  changes  induced  by  high 
temperature   beneath    great   pressure,    are   totally 
different  from  those  effected  by  fire  on  the  surface, 
under  the  ordinary  weight  of  the  atmosphere.     A 
familiar  example  will  serve  to  illustrate  my  meaning. 
Chalk  consists  of  lime  combined  with  carbonic  acid ; 
and  as  for  agricultural,  and  other  economical  pur- 
poses, it  is  desirable  to  have  the  lime  in  its  pure 
state,  the  chalk,  or  limestone,  is  exposed  to  a  great 
heat,  in  kilns  erected  in  the  open  air,  until  all  the 
carbonic  acid  gas  is  dissipated,  and  the  stone  is  said 
to  be  burnt  into  quick-lime.   In  the  specimens  before 
us,  the  same  substance  is  seen  in  the  state  both  of 
chalk  and  lime.   It  may  readily  be  conceived,  that  if 
this  operation  were  conducted  beneath  such  a  degree 
of  pressure  as  would  prevent  the  escape  of  the  gas, 
the  formation  of  quick-lime  would  not  take  place ; 


§  60.  EFFECTS  OF  HIGH  TEMPERATURE.  91 

the  chalk  would  be  fused,  and  the  carbonic  acid, 
released  from  its  present  relation  with  the  calcareous 
particles,  would  enter  into  other  combinations,  and 
the  mass  when  cooled,  be  wholly  different  from  the 
product  of  the  lime-kilns,  formed  by  the  same 
agency  in  the  open  air.  Experiments  have  proved 
that  this  opinion  is  correct.  Sir  James  Hall  exposed 
pounded  chalk  to  intense  heat,  under  great  pressure, 
and  it  was  fused,  not  into  lime,  but  into  crystalline 
marble :  even  the  shells  inclosed  in  the  chalk  under- 
went the  same  transmutation,  yet  preserved  their 
forms.  That  analogous  changes  have  been  effected 
by  natural  operations  we  have  abundant  proof;  but 
in  this  stage  of  our  inquiry  it  is  only  necessary  to 
remark,  that  where  ancient  streams  of  lava  have 
traversed  chalk,  the  latter  invariably  possesses  a 
crystalline  structure.  We  shall  hereafter  find,  in 
accordance  with  the  beautiful  and  philosophical 
theory  of  Dr.  Hutton,  that  all  the  strata  have  been 
more  or  less  modified  by  heat,  acting  under  great 
pressure  and  at  various  depths;  and  that  the  present 
position  and  direction  of  the  materials  composing 
the  crust  of  the  globe,  have  been  produced  by  the 
same  cause.*  The  Huttonian  theory,  indeed,  offers 
a  most  satisfactory  explanation  of  a  great  proportion 
of  geological  phenomena,  enabling  us  to  solve  many 
of  the  most  difficult  problems  in  the  science ;  and 
it  is  but  an  act  of  justice  to  the  memory  of  an 

*    See  Playfair's  Illustrations  of  the  Huttonian  Theory, 
vol.  i.  p.  33,  et  seg.  Edin.  1822. 


92  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

illustrious  philosopher,  and  of  his  able  illustrator, 
Professor  Play  fair,  to  state  that  this  theory,  cor- 
rected and  elucidated  by  the  light  which  modern 
discoveries  have  shed  upon  the  physical  history  of 
our  planet,  is  that  embraced  by  the  most  distin- 
guished modern  geologists. 

61.  VOLCANIC  AGENCY. — Of  the  activity  and 
power  of  the  agent  to  which  these  remarks  more 
immediately  refer,  the  currents  of  melted  rocks, 
called  lavas,  ejected  through  crevices  and  fissures 
of  the  earth,  accompanied  with  evolutions  of  heat 
and  vapour,  afford  the  most  striking  proofs ;  and 
the  volcano,  with  its  frequent  concomitant  the 
earthquake,  have  in  all  ages  excited  the  astonish- 
ment and  curiosity  of  mankind.  It  would  be 
foreign  to  the  design  of  this  discourse,  to  enter 
at  large  upon  the  nature  and  causes  of  volcanic 
action.  Dr.  Daubeny,*  Mr.  Scrope,f  and  others, 
have  published  highly  interesting  treatises  on  the 
subject ;  and  Mr.  Lyell  has  given  an  admirable 
sketch  of  volcanic  phenomena.  J  I  will  only  advert 
to  the  increased  temperature  of  the  earth  in  pro- 
portion as  we  descend  from  the  surface  towards 
the  interior,  and  the  profound  depths  from  which 
thermal  waters  take  their  rise,  as  tending  to  support 
the  opinion,  that  volcanic  eruptions  are  occasioned 
by  electro-chemical  changes,  which  are  constantly 

*  Daubeny' s  Lectures  on  Volcanoes,  1826. 
f  Scrope's  Considerations  on  Volcanoes,  1825. 
J  Principles  of  Geology,  vol.  ii. 


62,  63.  EFFECTS  OF  HEAT.  93 

going  on  in  the  interior  of  the  globe.  We  shall 
hereafter  have  occasion  to  demonstrate  that  dislo- 
cations of  the  strata,  with  elevations  of  the  bottom 
of  the  ocean,  and  eruptions  of  melted  mineral 
matter,  have  taken  place  from  the  earliest  geolo- 
gical periods  within  the  scope  of  our  inquiries.1 

62.  EXPANSION  OF  ROCKS  BY  HEAT. — The  ex- 
pansive power  of  caloric,  even  in  ordinary  circum- 
stances, is  very  considerable,  as  is  shown  by  the 
instrument  called  a  pyrometer,  which  illustrates  a 
fact  continually  presented  to  our  notice,  namely, 
the  expansion  of  a  bar  of  metal  by  heat,  and  its 
contraction,  by  cooling,  into  its  original  dimensions. 
The  expansion  of  solid  bodies  by  heat,  when  effected 
on  a  large  scale,   gives  rise  to  many  interesting 
phenomena.      The   careful  experiments  made  by 
Colonel  Totten,  on  the  expansion  of  granite,  marble, 
and  ether  rocks,  by  variations  of  temperature,  have 
shown  that  the  mere  expansion,  or  contraction,  of 
extensive  beds  of  these  materials,  will  account  for 
the  elevation  and  subsidence  of  considerable  tracts 
of  country,   and  explain  many  analogous  pheno- 
mena.* 

63.  TEMPLE  OF  JUPITER  SERAPIS. — One  of  the 
most  interesting  examples  of  local  elevation  and 
subsidence,  apparently  resulting  from  this  cause,  is 
that   afforded   by   the   celebrated   remains  of  the 
temple  of  Jupiter  Serapis,  at  Puzzuoli ;   and  which 
Mr.  Lyell,  by  selecting  as  the  subject  of  the  frontis- 

*  American  Journal  of  Science,  vol.  xxii. 


94 


THE  WONDERS  OF  GEOLOGY. 


LECT. 


piece  of  his  invaluable  work,  has  for  ever  associated 
with  the  Principles  of  Geology. 


TAB.  14. — TEMPLE  OF  JUPITER  SERAPIS, 
(From  Mr.  LyelCs  Principles  of  Geology.) 

These  ruins  are  situated  on  the  shore  of  the  Bay 
of  Baiae,  and  consist  of  the  remains  of  a  large 
building  of  a  quadrangular  form,  seventy  feet  in 
diameter ;  the  roof  of  which  was  supported  by 
twenty-four  granite  columns,  and  twenty-two  of 
marble,  each  formed  of  a  single  stone.  Many  of 
the  pillars  are  broken  and  strewed  about  the  pave- 
ment, but  three  remain  standing  nearly  erect,  and 


§  63.  TEMPLE  OF  JUPITER  SERAPIS.  95 

on  these  are  inscriptions,  not  traced  by  the  Greeks 
or  Romans,  but  by  some  of  the  simplest  forms  of 
animal  existence,  which  have  here  left  enduring 
records  of  the  physical  changes  that  have  taken  place 
on  these  shores,  since  man  erected  the  temple  in 
honour  of  his  gods.  The  tallest  column  is  forty-two 
feet  in  height ;  its  surface  is  smooth  and  uninjured 
to  an  elevation  of  about  twelve  feet  from  the  pede- 
stal, where  a  band  of  perforations  made  by  a  species 
of  marine  boring  muscle  (Modiolalithophaga)  com- 
mences, and  extends  to  the  height  of  nine  feet, 
above  which  all  traces  of  their  ravages  disappear.* 
The  perforations,  many  of  which  still  contain  shells, 
are  of  a  pear  shape,  and  are  so  numerous  and  deep 
as  to  prove  unquestionably  that  the  pillars  were 
immersed  in  sea-water,  at  the  very  time  when  the 
base  and  lower  portions  were  protected  by  rubbish 
and  tufa ;  and  that  the  upper  parts  projected  above 
the  waters,  and  consequently  were  placed  beyond 
the  reach  of  the  lithodomi.^  The  platform  of  the 
temple  is  now  about  one  foot  below  high-water 
mark ;  and  the  sea,  which  is  only  forty  yards  dis- 
tant, penetrates  the  intervening  soil.  The  upper 
part  of  the  band  of  perforations  is  therefore  at  least 
twenty-three  feet  above  the  level  of  the  sea ;  and 
yet  it  is  evident  that  the  columns  were  once  plunged 
in  salt  water  for  a  long  period.  It  is  equally  clear 
that  they  have  since  been  elevated  to  a  height  of 

*  See  Appendix  F. 

t  Lithodomi,  from  lithos,  stone,  and  demOf  to  build- 


96  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

twenty-three  feet,  still  maintaining  their  erect  posi- 
tion, amid  the  extraordinary  changes  which  they 
have  undergone,  and  incontrovertibly  proving  that 
the  relative  level  of  the  land  and  sea,  on  that  part 
of  the  coast,  has  changed  more  than  once  since  the 
Christian  era ;  each  movement,  both  of  subsidence 
and  elevation,  having  exceeded  twenty  feet.*  Yet 
there,  at  the  present  moment,  are  the  remains  of 
that  temple — 

"  Whose  lonely  columns  stand  sublime,1 

Flinging  their  shadows  from  on  high, 
Like  dials,  which  the  wizard  Time 
Had  raised  to  count  his  ages  by !  "  f 

Professor  Babbage  attributes  the  tranquil  eleva- 
tion and  depression  of  the  temple,  to  the  contraction 
and  expansion  of  the  strata  on  which  it  was  built. 
The  sources  of  volcanic  action  in  the  surrounding 
country  are  very  numerous,  and  a  hot  spring  still 
exists  on  the  land-side  of  the  ruins.  The  change  of 
level  is  therefore  easily  accounted  for,  by  supposing 
the  temple  to  have  been  built  on  the  surface  when 
the  rocks  were  expanded  by  the  effects  of  a  high 
temperature,  and  that  they  subsequently  contracted 
by  slow  refrigeration.  When  this  contraction  had 
reached  a  certain  point,  a  fresh  accession  of  heat 
from  the  neighbouring  volcano  increased  the  tem- 
perature of  the  strata;  which  again  expanded  and 
raised  the  ruins  to  their  present  level.  J 

*  Principles  of  Geology,  vol.  ii.  p.  268. 
f  Moore.  J  Appendix  G. 


§  63.  TEMPLE  OF  JUPITER  SERAPIS.  97 

Mr.  Babbage  carries  out  these  views  to  explain 
the  elevation  of  continents  and  mountain  ranges, 
assuming  the  following  facts  as  the  basis  of  his 
theory : — 

1st.  As  we  descend  below  the  surface  of  the 
earth,  the  temperature  increases. 

2dly.  Solid  rocks  expand  by  being  heated,  but 
clay  and  some  other  substances  contract. 

3dly.  Rocks  and  strata  of  dissimilar  characters 
present  a  corresponding  difference  as  conductors  of 
caloric. 

4thly.  The  radiation  of  heat  from  the  earth  varies 
in  different  parts  of  its  surface ;  according  as  it  is 
covered  by  forests,  mountains,  deserts,  or  water. 

5thly.  Existing  atmospheric  agents,  and  other 
causes,  are  constantly  changing  the  condition  of  the 
surface  of  the  globe. 

Thus  wherever  a  sea  or  lake  is  filled  up  by  the 
wearing  down  of  the  adjacent  lands,  new  beds  are 
formed,  conducting  heat  much  less  quickly  than  the 
water  ;  while  the  radiation  from  the  surface  of  the 
new  land  will  also  be  different.  Hence,  any  source 
of  caloric,  whether  partial  or  central,  which  pre- 
viously existed  below  that  sea,  must  increase  the 
temperature  of  the  strata  underneath  to  a  mucli 
higher  degree'  than  before,  because  they  are  now 
protected  by  a  bad  conductor;*  and  their  expansion 

*  Sir  John  Herschel  observes,  that  this  process  is  precisely 
similar  to  that  by  which  a  great  coat,  in  a  wintry  day,  increases 
the  feeling  of  warmth ;   the  flow  of  heat  outwards  being  ob- 
H 


98  THE  WONDERS  OF  GEOLOGY.  LECT  I. 

must  therefore  elevate  the  newly-formed  deposits 
above  their  former  level; — thus  the  bottom  of  an 
ocean  may  become  a  continent.  The  whole  ex- 
pansion, however,  resulting  from  the  altered  cir- 
cumstances, may  not  take  place  until  long  after  the 
filling  up  of  the  sea;  in  which  case  its  conversion 
into  dry  land  will  result  partly  from  the  accumu- 
lation of  detritus,  and  partly  from  the  elevation  of 
the  bottom.  As  the  heat  now  penetrates  the  newly- 
formed  strata,  a  different  action  may  be  induced ; 
the  beds  of  clay  or  sand  may  become  consolidated, 
and  instead  of  expanding,  may  contract.  In  this 
case,  either  large  depressions  will  occur  within  the 
limits  of  the  new  continent,  or  after  another  in- 
terval, the  new  land  may  again  subside,  and  form  a 
shallow  sea.  This  sea  may  be  again  filled  up  by  a 
repetition  of  the  same  processes  as  before; — and 
thus  alternations  of  marine  and  fresh-water  deposits 
may  occur,  having  interposed  between  them  the 
productions  of  the  dry  land.* 

To  review  the  physical  changes  which  are  still 
taking  place  around  the  Bay  of  Naples  would  prove 
highly  interesting,  but  my  limits  will  only  permit 
me  to  observe,  that  whole  mountains  have  been 
elevated  on  the  one  hand,  and  temples  and  palaces 
have  sunk  beneath  the  sea  on  the  other.  In  our 

structed,  and  the  surface  of  congelation  removed  to  a  distance 
from  the  body,  by  the  heat  thereby  accumulated  beneath  the 
new  covering. 

*  Proceedings  of  the  Geological  Society,  March  1834. 


§  64.  ELEVATION  OF  THE  COAST  OF  CHILI.  yQ 

sister  island  we  have  evidence  of  former  changes 
of  a  like  nature,  and  which  are  alluded  to  by  our 
inimitable  lyric  poet,  in  the  following  beautiful 
lines : — 

On  Lough  Neagh's  banks  as  the  fisherman  strays, 

When  the  clear  cold  eve's  declining, 
He  sees  the  round  towers  of  other  days, 

In  the  wave  beneath  him  shining ! 

Thus  shall  memory  often,  in  dreams  sublime, 
Catch  a  glimpse  of  the  days  that  are  over ; 

Thus,  sighing,  look  through  the  waves  of  time 
For  the  long  faded  glories  they  cover ! 

64«.  ELEVATION  OF  THE  COAST  OF  CHILI. — One 
of  the  most  remarkable  modern  instances  of  the 
elevation  of  an  extensive  tract  of  country,  is  that 
recorded  by  Mrs.  Maria  Graham,*  as  having  been 
produced  by  the  memorable  earthquake  which 
visited  Chili  in  1822,  and  continued  at  short  in- 
tervals till  the  end  of  1823.  The  shocks  were  felt 
through  a  space  of  1,200  miles,  from  north  to  south. 
At  Valparaiso,  on  the  morning  of  the  20th  of 
November,  it  appeared  that  the  whole  line  of  coast 
had  been  raised  above  its  level ;  an  old  wreck  of  a 
ship,  which  could  not  previously  be  approached, 
was  now  accessible  from  the  land;  and  beds  of 
scallops  were  brought  to  light,  which  were  not 
before  known  to  exist.  "  When  I  went  to  examine 
the  coast,"  says  Mrs.  Graham,  "  although  it  was 
high- water,  I  found  the  ancient  bed  of  the  sea  laid 
*  Now  Mrs.  Calcott. 
H2 


100  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

bare  and  dry,  with  oysters,  muscles,  and  other 
shells,  adhering  to  the  rocks  on  which  they  grew : 
the  fish  being  all  dead,  and  exhaling  the  most  of- 
fensive effluvia.  It  appeared  to  me,  that  there  was 
every  reason  to  believe  the  coast  had  been  raised 
by  earthquakes  at  former  periods,  in  a  similar 
manner;  for  there  were  several  lines  of  beach, 
consisting  of  shingle  mixed  with  shells,  extending 
in  parallel  lines  to  the  shore,  to  the  height  of  fifty 
feet  above  the  sea."  *  Part  of  the  coast  thus 
elevated  consists  of  granite  ;  and  subsequent  ob- 
servations have  proved  that  the  whole  of  the  country 
was  raised,  from  the  foot  of  the  Andes  to  far  out 
at  sea;  the  supposed  area  over  which  the  elevatory 
movements  extended,  being  about  100,000  square 
miles ;  a  space  equal  in  extent  to  half  the  kingdom 
of  France,  Mrs.  Somerville  mentions,  that  a  further 
elevation  to  a  considerable  extent  has  also  taken 
place  along  the  Chilian  coast,  in  consequence  of 
the  violent  earthquake  of  1835. 

65.  LIFTED  SEA  BEACH  AT  BRIGHTON.  —  Ex- 
amples of  such  changes  occur  in  almost  every  part 
of  the  world ;  and  there  is  perhaps  no  considerable 
extent  of  country  which  does  not  afford  some  proof 
that  similar  physical  mutations  have  taken  place  in 
modern  times.  And  although  I  cannot  point  out 
to  you  a  temple  of  Serapis  on  our  shores,  yet  within 
a  few  hundred  yards  of  Brighton,  there  is  un- 
questionable evidence  that  the  relative  level  of  land 
*  Geological  Transactions,  vol.  i.  second  series. 


§65.  LIFTED  SEA  BEACH  AT  BRIGHTON.  10l' 

and  sea,  has  undergone  great  changes  within,  to 
speak  geologically,  a  comparatively  recent  period. 
The  upper  part  of  the  cliffs,  extending  from  the 
commencement  of  the  low  range  by  Shoreham, 
to  Rottingdean,  is  composed  of  chalk  with  rubble, 
flints  slightly  rolled,  and  clay  and  loam ;  the  whole 
being  clearly  an  accumulation  of  water-worn  mate- 
rials, deposited  in  an  estuary  or  bay  of  the  sea. 
The  base  of  the  cliffs,  to  the  height  of  a  few  feet, 
is  composed  of  the  solid  chalk,  which  may  be  seen 
at  low  water  extending  far  out  to  sea,  and  is  covered 
here  and  there  by  shingle  and  sand.  Between  the 
chalk  and  the  superincumbent  mass  just  described, 
is  a  bed  of  shingle,  composed  of  rolled  chalk,  flints, 
pebbles,  and  sand,  with  boulders  of  granite,  por- 
phyry, and  other  rocks,  not  now  met  with  on  those 
shores;  in  fact,  an  ancient  sea  beach,  formed  at 
some  remote  epoch,  in  like  manner  as  the  present 
bed  of  shingle,  which  skirts  the  base  of  the  cliffs, 
is  in  the  progress  of  formation.  Among  the  pebbles 
of  this  ancient  beach,  are  rolled  masses  of  chalk 
and  limestone,  which  are  full  of  perforations  made 
by  boring  shells  ;  here  are  several  specimens,  which 
are  similar  to  those  made  in  the  chalk-rock  by 
the  recent  pholades  and  mytili.  As  I  shall  have 
occasion  to  revert  to  these  cliffs  in  the  next  lecture, 
this  brief  description  will  suffice  for  our  present 
purpose. 

The  following  diagram  represents  a  natural  ver- 
tical section  of  the  cliffs,  as  seen  in  those  parts 


102  THfi  V^dNlJEAS  OF  GEOLOGY.  LECT.  I. 

where  the  inroads  of  the  sea  have  extended  to  the 
chalk  strata,   and  the  face  of  the  ancient  cliff  is 


The  Sea. 


TAB.  15. — ELEVATED  BEACH  AT  BRIGHTON,  EAST  OF  KEMP  TOWN. 
A,  Elephant  bed;  B,  ancient  bed  of  shingle ;  C,  the  chalk. 

exposed,  the  new  deposits  being  shown  in  profile ; 
these  consist  of  the  following  beds : — 

1.  (A)    Chalk,   rubble,    loam,    &c.,    obscurely 
stratified;   this  deposit,  from  its  containing  teeth 
and  bones  of  elephants,   is  called  the  Elephant- 
bed;   it  constitutes  the  upper  three-fourths  of  the 
cliffs. 

2.  (B)   Shingle,  or  sea  beach  and  sand,  many 
feet  above  high-water  mark.     This  ancient  shingle, 
which  from  the  inroads  of  the  sea  extends  in  the 
cliffs   beyond   Kemp   Town   but  a  short  distance 
inland,  is  constantly  found  beneath  the  loam  and 
clay,  several  hundred  yards  from  the  shore  in  the 
western  part  of  Brighton.     In  a  well  lately  dug  in 
the  Western  road,  the  shingle  bed  was  reached  at 
the  depth  of  fifty-four  feet. 


§65.  LIFTED  SEA  BEACH  AT  BRIGHTON.  103 

3.  (c)  The  undisturbed  chalk,  which  forms  a 
sloping  cliff,  inland,  or  behind  the  beds  (A)  and  (B), 
passes  under  the  ancient  sea  beach,  and  appears  as 
a  terrace  at  the  foot  of  the  present  cliffs.* 

These  appearances  demonstrate  the  following 
sequence  of  changes  in  the  relative  level  of  the 
land  and  sea  on  the  Sussex  shores : — 

First.  The  chalk  terrace  on  which  the  ancient 
shingle  rests,  was  on  a  level  with  the  sea  for  a  long 
period ;  and  the  beach  was  formed,  like  the  modern 
beach,  by  the  action  of  the  waves  on  the  then  ex- 
isting cliffs.  The  rolled/condition  of  the  materials, 
and  the  borings  of  the  lit/wdomi,  prove  a  change  of 
level  as  decidedly  as  do  the  perforations  in  the 
columns  of  the  temple  of  Serapis. 

Secondly.  The  whole  line  of  coast,  with  the 
shingle  (B),  was  submerged  to  such  a  depth,  as  to 
admit  the  deposition  of  the  strata  (A)  above  them. 

Lastly.  The  cliffs  were  raised  to  their  present 
elevation,  and  at  this  period  the  formation  of  the 
existing  sea  beach  commenced. 

The  elevation  of  the  sea-shore  with  beds  of  marine 
shells,  already  alluded  to  as  having  been  produced 
by  earthquakes  on  the  Chilian  coast,  has  here  then 
a  parallel.  A  phenomenon  of  a  like  nature,  but  of 
a  far  more  ancient  period,  is  observable  at  Castle 
Hill,  near  Newhaven,  about  eight  miles  east  of 
Brighton,  where  is  seen  immediately  beneath  the 

*  See  Geology  of  the  South- East  of  England,  p.  30 ;  and 
Fossils  of  the  South  Downs,  p.  277. 


104  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

turf,  a  regular  sea  beach  with  beds  of  oyster-shells, 
many  feet  in  thickqess,  lying  on  the  summit  of  the 
chalk  cliffs,  150  feet  above  the  level  of  the  sea. 
Near  Bromley,  in  Kent,  and  at  Reading,  in  Berk- 
shire, similar  accumulations  of  beach  and  oyster- 
shells  are  to  be  found.  Elevated  shingles,  of 
comparatively  recent  epochs,  occur  on  the  shores 
of  the  Frith  of  Forth,  and  also  along  the  western 
coasts  of  England,  as  Mr.  Murchison  has  satis- 
factorily demonstrated. 

66.  ELEVATION  OF  SCANDINAVIA.  —  Having 
thus  adduced  a  few  striking  proofs  of  the  mutations 
which  the  land  has  undergone  in  past  times,  we  are 
led  to  enquire — Is  this  change  still  going  on  ?  Is 
the  alternate  subsidence  and  elevation  of  the  land 
the  effect  of  a  law  of  nature,  established  from  the 
existence  of  the  present  condition  of  our  planet, 
and  destined  to  continue  in  action  while  its  physical 
constitution  remains  the  same  ?  We  shall  hereafter 
find,  that  this  law  has  been  in  constant  action  from 
the  earliest  periods  of  the  earth's  history,  of  which 
her  physical  monuments  afford  any  indications;  and 
I  now  proceed  to  adduce  an  instance  in  which  the 
elevation  of  a  whole  country  is  actually  taking 
place,  unheeded  by  the  busy  multitude,  and  known 
only  by  the  researches  of  the  natural  philosopher. 
I  allude  to  Scandinavia,  which,  it  is  ascertained,  is 
slowly  and  visibly  rising,  from  Frederickshall,  in 
Sweden,  to  Abo,  in  Finland,  and  even,  perhaps,  as 
far  as  St.  Petersburgh  ;  while  the  adjacent  coast  of 


§  66.  ELEVATION  OF  SCANDINAVIA.  105 

Greenland  is  suffering  a  gradual  depression.  The 
state,  therefore,  is  one  of  oscillation,  the  waters 
appearing  to  sink  at  Torneo,  and  to  retain  their 
former  level  at  Copenhagen.  The  opinion  that 
Sweden  is  in  this  state  of  change,  is  no  new  idea ; 
it  was  long  since  noticed  by  Celsius,*  and  other 
Swedish  philosophers.  Mr.  Lyell  has  twice  visited 
Scandinavia  within  the  last  few  years,  with  the  view 
of  determining  this  interesting  question ;  and  has 
fully  convinced  himself  that  certain  parts  of  Sweden 
are  undergoing  a  gradual  rise,  to  the  amount  of 
two  or  three  feet  in  a  century  ;  while  other  parts, 
farther  to  the  south,  appear  to  have  experienced  no 
movement.-}1  He  visited  some  parts  of  the  shores 
of  the  Bothnian  Gulf,  between  Stockholm  and  Gefle, 
and  of  the  western  coasts  of  Sweden,  districts  par- 
ticularly alluded  to  by  Celsius.  He  examined  the 
marks  cut  by  the  Swedish  pilots,  under  the  direc- 
tion of  the  Swedish  Academy  of  Sciences,  in  1820, 
and  found  the  level  of  the  Baltic,  in  calm  weather, 
to  be  several  inches  lower  than  the  marks,  and 
several  feet  below  those  made  seventy  or  a  hundred 
years  ago.  Similar  results  were  obtained  on  the 
side  of  the  ocean,  and  in  both  districts  the  testi- 
mony of  the  inhabitants  agreed  with  that  of  their 
ancestors,  recorded  by  Celsius.  On  the  shores  of 
the  Northern  Sea,  there  are  banks  of  recent  shells, 

•  Illustrations  of  the  Huttonian  Theory,  p.  436,  edit  1822. 
t  Philosophical  Transactions.    Principles  of  Geology,  Fifth 
Edition,  vol.  ii.  p.  286. 


106  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

at  various  heights,  from  10  to  200  feet,  and  on  the 
side  of  the  Bothnian  Gulf,  between  Stockholm  and 
Gefle,  deposits  containing  fossil  shells  of  the  species 
which  now  inhabit  the  brackish  waters  of  that  sea. 
These  occur  at  various  elevations,  from  one  to  a 
hundred  feet,  and  sometimes  extend  fifty  miles 
inland.  The  shells  are  partly  marine  and  partly 
fluviatile ;  the  marine  species  are  identical  with 
those  now  living  in  the  ocean,  but  are  dwarfish  in 
size,  and  never  attain  the  average  dimensions  of 
those  which  live  in  water  sufficiently  salt  to  enable 
them  to  reach  their  full  development.  The  speci- 
mens before  you  were  collected  by  Mr.  Lyell  at 
Uddevalla,  in  Sweden,  from  the  summit  of  cliffs 
twenty  feet  above  the  level  of  the  sea ;  they  consist 
of  recent  marine  species,  such  as  inhabit  the  neigh- 
bouring waters. 

Of  the  reality  of  these  changes  in  the  relative 
level  of  the  land  and  of  the  Northern  ocean,  there 
cannot  exist  a  doubt ;  but  the  mind  is  so  accus- 
tomed to  associate  the  idea  of  stability  with  the 
land,  and  of  mutability  with  the  sea,  that  it  may 
be  necessary  to  offer  a  few  additional  remarks  on 
these  highly  interesting  facts.  As  it  is  the  property 
of  all  fluids  to  find  their  own  level,  it  is  obvious 
that  if  the  level  of  the  sea  be  elevated  or  depressed 
in  any  one  part,  that  elevation  or  depression  must 
influence  the  whole  surface  of  the  ocean,  and  the 
level  therefore  cannot  be  affected  by  local  causes. 
But  movements  of  the  land  may  take  place,  and 


§66.  ELEVATION  OF  SCANDINAVIA.  107 

the  effect  extend  over  whole  countries,  as  in  South 
America, — or  along  lines  of  coast,  as  in  Sussex, — 
or  be  confined  to  a  single  island, — or  even  to  the 
broken  columns  of  a  temple,  as  at  Puzzuoli.*  But 
while  the  land  is  rising  in  the  more  northern  lati- 
tudes, it  appears  to  be  sinking  on  the  shores  of  the 
Mediterranean.  Breislak  mentions -f-  that  numerous 
remains  of  buildings  are  to  be  seen  in  the  Gulf  of 
Baiae ;  ten  columns  of  granite,  at  the  foot  of  Monte 
Nuovo,  are  nearly  covered  by  the  sea,  as  are  the 
ruins  of  a  palace  built  by  Tiberius  in  the  island  of 
Caprea.  Thus,  while  the  level  of  the  sea  is  becoming 
lower  in  the  north,  it  is  rising  in  the  Mediterranean  ; 
and  as  all  the  parts  of  the  ocean  communicate,  the 
sea  cannot  permanently  rise  in  one  part  and  sink 
in  another,  but  must  rise  and  fall  equally  to  main- 
tain its  level ;  we  must  therefore  consider  it  as 
demonstrated,  that  these  changes  have  proceeded 
from  the  elevation  and  depression  of  the  land.  If 
we  bear  in  mind  the  insignificance  of  the  masses 
affected  by  these  operations,  as  contrasted  with  the 
earth  itself  (see  page  14),  we  may  readily  conceive 
that  as  fissures  and  inequalities  are  produced  in  the 
varnish  of  an  artificial  globe  by  heat  and  cold,  in 
like  manner  the  elevation  of  mountain  chains,  the 
rending  of  extensive  tracts  of  country,  and  the  sub- 
sidence of  whole  continents,  may  be  occasioned  by 

«   See  Playfair's  admirable   comments   on   this   geological 
problem. — Illustrations,  p.  433. 
t  Playfair. 


108  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

the  expansion  and  contraction  of  the  materials  of 
which  our  planet  is  constructed. 

67.  RETROSPECT. — In  this  imperfect  sketch  of 
the  geological  phenomena,  which  a  superficial  ex- 
amination of  the  surface  of  the  globe  presents  to 
our  notice,  I  have  doubtless  dwelt  on  several  sub- 
jects which  are  familiar  to  many  of  my  auditors. 
But,  as  one  of  our  ablest  geologists*  has  remarked, 
"  the  teacher  of  Geology  must  suppose  himself 
called  on  to  answer  questions  both  concerning  the 
facts  of  the  science  and  the  inferences  to  be  deduced 
therefrom ;  and  his  instructions  will  be  so  much  the 
more  successful  as  he  takes  these  questions  in  the 
most  natural  order  of  their  occurrence,  and  answers 
them  most  completely  and  satisfactorily.  In  doing 
this  he  is  not  at  liberty  to  neglect  even  elementary 
truths,  for  if  these  were  passed  over  in  compliment 
to  such  as  have  made  progress  in  the  science,  those 
for  whose  advantage  he  is  especially  interested, 
would  be  called  to  the  unreasonable  task  of  labour- 
ing without  instruments,  and  of  theorizing  without 
intelligible  data." 

From  the  vast  field  of  inquiry  over  which  our 
observations  have  extended,  it  may  be  useful  to 
offer  a  brief  summary  of  the  leading  principles  that 
have  been  enunciated,  and  the  facts  on  which  they 
are  founded.  By  the  most  profound  and  sublime 
investigations  of  which  the  human  mind  is  capable, 
we  learn  that  our  earth  is  one  of  myriads  of 
*  Professor  Phillips. 


§67.  RETROSPECT.  109 

spherical  bodies,  revolving  round  certain  luminaries  ; 
and  that  these  bodies  occur  in  every  variety  of  con- 
dition, from  that  of  a  diffuse  luminous  vapour,  to 
opaque  solid  globes  like  our  own.  All  the  mate- 
rials of  which  the  earth  is  composed  may  exist 
either  in  a  solid,  fluid,  or  gaseous  state  ;  and  simply 
by  a  change  of  temperature,  or  by  electro-chemical 
agency,  every  substance  may  undergo  a  transition 
from  one  state  to  the  other.  Water  existing  as  ice, 
fluid,  or  vapour,  and  separable  into  two  invisible 
gases,  offers  a  familiar  example  of  a  body  constantly 
exhibiting  these  changes ;  and  mercury,  of  a  metal 
which,  although  generally  fluid,  or  melted,  becomes, 
when  exposed  to  a  very  low  temperature,  a  solid 
mass  like  silver.  The  relative  position  of  land  and 
water,  and  the  inequalities  on  the  surface  of  the 
earth,  are  subject  to  constant  changes,  which  are 
regulated  by  certain  fixed  laws.  The  principal 
causes  of  the  degradation  of  the  land  are  atmo- 
spheric agencies,  variations  of  temperature,  and  the 
action  of  running  water,  by  which  the  disintegrated 
materials  of  the  land  are  carried  into  the  bed  of  the 
ocean.  The  mud,  sand,  and  other  detritus  thus 
produced,  are  consolidated  by  certain  chemical 
changes  which  are  in  constant  activity,  both  on  the 
land  and  in  the  depths  of  the  ocean,  and  new  rocks 
are  thus  in  the  progress  of  formation.  But  the 
conjoint  effect  of  these  disintegrating  agencies  is 
unremitting  destruction  of  the  land ;  and  were  there 
no  conservative  process,  the  whole  of  the  dry  land 


110  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

would  disappear,  and  the  earth  be  covered  by  one 
vast  sheet  of  water.  The  globe,  however,  possesses 
an  internal  source  of  heat, — and  whether  this  heat 
exist  as  a  central  nucleus  of  high  temperature,  or  as- 
medial  foci,— whether  it  be  dependent  on  the  assumed 
original  nebulous  state  of  the  earth,  or  produced 
by  electro-magnetic  forces  acting  on  the  mineral 
substances  contained  in  the  interior  of  our  planet, — 
does  not  affect  the  present  inquiry.  This  internal 
heat,  however  produced,  must  occasion  constant 
changes  in  the  relative  level  of  the  land  and  water ; 
elevating  whole  continents, — converting  the  bed  of 
the  sea  into  dryland, — and  submerging  the  dry 
land  into  the  abyss  of  the  ocean.  The  volcano  and 
the  earthquake  are  the  effects  of  its  paroxysmal 
energies, — the  quiet  and  insensible  elevation  of  the 
land,  of  its  slow  but  certain  operation.  By  this 
antagonist  power  the  accumulation  of  the  spoils  of 
the  land,  which  the  rivers,  waves,  and  currents 
have  carried  into  the  bed  of  the  ocean,  are  again 
brought  to  the  surface,  and  form  the  elements  of 
new  islands  and  continents  ;  and  by  the  organic 
remains  discovered  in  these  strata,  we  trace  the 
nature  of  the  countries  from  whence  these  spoils 
were  derived.  In  the  deltas  and  estuaries  of  modern 
times, — in  the  detritus  accumulating  in  the  beds  of 
the  ocean, — in  the  recent  tracts  of  limestone  form- 
ing on  the  sea-shores, — beneath  the  cooled  lava 
currents  erupted  from  existing  volcanoes, — the  re- 
mains of  man  and  of  his  works,  and  of  the  animals 


§67.  RETROSPECT.  HI 

and  plants  which  are  his  contemporaries,  are  found 
imbedded. 

The  dynamical  effects  of  elevation  appear  to  be 
referable  to  three  great  divisions: — 1.  The  gradual 
raising  up  of  ridges  through  large  spaces  of  the 
earth's-  crust,  and  the  consequent  production  of 
longitudinal  fissures  and  lines  of  volcanic  vent. 
2.  The  long  continued  protrusion  and  eruption  of 
igneous  rocks  along  such  lines  of  vent ;  and  3.  Local 
and  partial  eruptions  and  protrusions,  producing 
valleys  of  elevation,  dislocations  of  the  strata,  and 
other  phenomena  that  terminate  in  ordinary  volcanic 
action.* 

Such  are  the  deductions  derived  from  the  phe- 
nomena which  have  been  submitted  to  our  exami- 
nation. 

To  the  mind  previously  uninstructed  in  geological 
science,  I  am  ready  to  acknowledge  that  to  attribute 
mutability  to  the  rocks  and  the  mountains,  must 
appear  as  startling  and  incredible,  as  did  the  astro- 
nomical doctrines  of  Galileo  to  the  people  of  his 
time.  But  the  intelligent  observer,  whose  atten- 
tion has  been  directed  to  the  facts  laid  before  him 
even  in  this  brief  survey,  cannot,  I  conceive,  refuse 
his  assent  to  the  inferences  thus  cautiously  obtained. 
As  we  proceed  in  our  investigation,  we  shall  find 
that  from  the  earliest  period  of  the  earth's  physical 
history,  its  surface  has  been  subject  to  incessant 
fluctuation ;  and  as  the  land  has  been  the  theatre 
*  Proceedings  of  the  Geological  Society,  vol.  ii.  p.  67. 


112  THE  WONDERS  OF  GEOLOGY.  LECT.  I. 

of  perpetual  mutation,  that  element,  which  has 
hitherto  been  considered  as  the  type  of  mutability, 
can  alone  be  regarded  as  having  undergone  no 
change.  This  idea  is  finely  embodied  by  Lord 
Byron  in  the  following  sublime  apostrophe  to  the 
Ocean,  with  which  I  will  conclude  this  discourse. 

"  Thy  shores  are  empires,  changed  in  all  save  thee — 
Assyria,  Greece,  Rome,  Carthage,  what  are  they  ? 
Thy  waters  wasted  them  while  they  were  free, 
And  many  a  tyrant  since  ;  their  shores  obey 
The  stranger,  slave,  or  savage  ;   their  decay 
Has  dried  up  realms  to  deserts  : — not  so  thou, 
Unchangeable,  save  to  thy  wild  waves'  play — 
Time  writes  no  wrinkle  on  thine  azure  brow — 
Such  as  Creation's  dawn  beheld,  thou  rollest  now  .'" 


LECTURE   II. 

1.  Introductory  observations.  2.  Extinction  of  animals.  3.  Animals 
extirpated  by  human  agency.  4.  The  apteryx  australis.  5.  The  dodo. 
6.  The  Irish  elk.  7.  Epoch  of  terrestrial  mammalia.  8.  Character 
of  the  ancient  alluvial  deposits.  9.  Classification  of  mammalian  re- 
mains. 10.  Comparative  anatomy.  11.  Adaptation  of  structure  in 
animals.  12.  Osteological  characters  of  the  carnivora.  13.  Structure 
of  the  hcrbivora.  14.  Structure  of  the  rodentia,  or  gnawers.  15. 
General  inferences.  1C.  Fossil  bones.  17.  Fossil  elephants,  or  mam- 
moths. 18.  Mammoth  and  rhinoceros  in  ice.  19.  Teeth  of  recent, 
and  fossil  elephants.  20.  The  mastodon.  21.  Mastodons  from  the 
Burmese  empire.  22..  The  sivatherium.  23.  The  megatherium.  24. 
The  megalonyx.  25.  The  sloth.  26.  Fossil  hippopotamus,  rhinoceros, 
horse,  &c.  27.  The  dinotherium.  28.  Fossil  carnivora  in  caverns. 
29.  Cave  of  Gaylenreuth.  30.  Forster's  Hohle.  31.  Bone  caverns  in 
England. — Kirkdale  cave.  32.  Diseased  bones  of  carnivora  found 
in  caves.  33.  Human  bones,  and  works  of  art  in  caverns.  34.  Osseous 
breccia,  or  bone  conglomerates.  35.  The  rock  of  Gibraltar.  36.  Osseous 
breccia  of  Australia.  37.  Retrospect. 

1.  INTRODUCTORY  OBSERVATIONS.  —  In  the  pre- 
vious lecture  we  took  a  comprehensive  view  of 
the  actual  physical  condition  of  the  surface  of  our 
planet,  and  of  the  nature  and  results  of  the  prin- 
cipal agents  by  which  the  land  is  disintegrated  and 
renewed.  We  found  in  the  modern  fluviatile  and 
marine  deposits,  that  the  remains  of  man,  of  works 
of  art,  and  of  the  existing  races  of  animals,  were 
preserved.  In  every  step  of  our  progress,  the  grand 
law  of  nature,  alternate  decay  and  renovation,  was 
exemplified  in  striking  characters — whether  in  the 


114  THE  WONDERS  OF  GEOLOGY.  Leer.  II. 

regions  of  eternal  snow,  or  in  torrid  climes — in  the 
rocks  and  mountains,  or  in  the  verdant  plains — by 
the  agency  of  heat,   or  by  the  effect  of  cold — of 
drought,  or  of  moisture — of  steam,  or  of  vapour — 
by  the  abrasion  of  torrents  and  rivers — by  inunda- 
tions of  the  ocean — or  by  volcanic  eruptions — still 
the  work  of  destruction,  in  every  varying  character, 
was  apparent.    And  on  the  other  hand  we  perceived 
that  amidst  all  these  processes  of  decay  and  deso- 
lation, perpetual  renovation  was  at  the  same  time 
going  on, — and  that  Nature  was  repairing  her  ruins, 
and  accumulating  fresh  materials  for  new  islands 
and  continents ;    and  that  innumerable  living  in- 
struments were  employed  to  consolidate,  and  build 
up  the  rocky  fabric  of  the  earth ;  and  that  even  the 
most  terrific  of  physical  phenomena,  the  earthquake, 
and  the  volcano,  were  but  salutary  provisions  of  the 
Supreme  Cause,  by  which  the  harmony  and  integrity 
of  our  planet  were  maintained   and  perpetuated. 
The    occurrence   of   human   skeletons   in   modern 
limestone — of  coins   and  works   of  art   in   recent 
breccia — and  the  preservation  of  the  bones  of  ex- 
isting species  of  animals,  and  of  the  leaves  and 
branches  of  vegetables,  in  the  various  deposits  that 
are  in  progress,  incontestably  prove  that  enduring 
memorials  of  the  present  state  of  animated  nature 
will  be  transmitted  to  future  ages.     When  the  beds 
of  the  existing  seas  shall  be  elevated  above  the 
waters,  and  covered  with  woods  and  forests — when 
the   deltas  of  our  rivers  shall  be  converted   into 


§2.  EXTINCTION  OF  ANIMALS.  115 

fertile  tracts,  and  become  the  sites  of  towns  and 
cities — we  cannot  doubt  that  in  the  materials,  ex- 
tracted for  their  edifices,  the  then  existing  races  of 
mankind  will  discover  indelible  records  of  the  phy- 
sical history  of  our  times,  long  after  all  traces  of 
those^  stupendous  works,  upon  which  we  vainly 
attempt  to  confer  immortality,  shall  have  disap- 
peared. But  we  must  now  proceed,  and  pass  from 
the  ephemeral  productions  of  man,  to  the  enduring 
monuments  of  nature — from  the  coins  of  brass  and 
silver,  to  the  imperishable  medals  on  which  the  past 
events  of  the  globe  are  inscribed — from  the  moulder- 
ing ruins  of  temples  and  palaces,  to  the  examination 
of  the  mighty  relics,  which  the  ancient  revolutions 
of  the  earth  have  entombed. 

2.  EXTINCTION  OF  ANIMALS. — Before  entering 
upon  the  consideration  of  the  geological  phenomena, 
which  belong  to  the  period  immediately  antecedent 
to  the  present,  it  will  be  necessary  to  notice  one  of 
the  most  remarkable  facts  which  geological  inves- 
tigations have  established, — namely,  the  entire  ob- 
literation of  certain  genera  of  animals  and  plants. 
The  fluctuating  state  of  the  earth's  surface,  with 
which  our  previous  inquiries  have  made  us  familiar, 
will  have  prepared  us  for  the  disappearance  of  some 
species  of  animals ; — and  here  another  law  of  the 
Creator  is  manifest.  Certain  races  of  living  beings, 
suitable  to  peculiar  conditions  of  the  earth,  appear 
to  have  been  created ;  and  when  those  states  became 
no  longer  favourable  for  the  continuance  of  such 
i  2 


HG  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

types  of  organization,  according  to  the  natural  laws 
by  which  the  conditions  of  their  existence  were 
determined,  the  races  disappeared,  and  were  pro- 
bably succeeded  by  new  forms. 

The  extinction  of  whole  genera  of  animals  and 
plants  has  no  doubt  depended  on  many  causes-  In 
the  earlier  ages,  the  changes  of  temperature,  and  the 
rapid  mutations  of  land  and  water,  were  probably 
the  principal  agents  of  destruction  ;  but  since  man 
became  the  lord  of  the  creation,  his  necessities  and 
caprice  have  occasioned  the  extirpation  of  whole 
tribes  of  animals,  whose  relics  are  found  in  the 
superficial  strata,  with  those  of  species  concerning 
which  both  history  and  tradition  are  silent. 

In  this  country  the  beaver,  wolf,  hyena,  bear,  &c. 
are  examples  of  species  which,  although  extinct  in 
Great  Britain,  still  exist  elsewhere;  while  the  mam- 
moth, and  the  Irish  elk,  whose  remains  occur  in 
our  alluvial  deposits,  are  both  extinct ;  the  latter 
was  unquestionably  extirpated  by  the  early  inha- 
bitants of  these  islands.  The  obliteration  of  certain 
forms  of  organization,  is  therefore  clearly  dependent 
on  a  law  in  the  economy  of  nature  which  is  still 
in  active  operation  ;  and  I  shall  proceed  to  notice 
the  connecting  links  between  the  actually  existing 
species,  and  those  which  are  blotted  out  from  the 
face  of  the  earth. 

3.  ANIMALS  EXTIRPATED  BY  HUMAN  AGENCY. 
— That  the  extinction  of  many  of  the  existing  races 
of  animals  must  soon  take  place,  from  the  immense 


§4.  APTERYX  AUSTRALIS.  117 

destruction  occasioned  by  man,  cannot  admit  of 
doubt.  In  those  which  supply  fur,  a  remarkable 
proof  of  this  inference  is  cited  in  a  late  number  of 
the  American  Journal  of  Science.  "  Immediately 
after  South  Georgia  was  explored  by  Captain  Cook, 
in  1771,  the  Americans  commenced  carrying  seal- 
skins from  thence  to  China,  where  they  obtained 
most  exorbitant  prices.  One  million  two  hundred 
thousand  skins  have  been  taken  from  that  island 
alone,  since  that  period ;  and  nearly  an  equal  number 
from  the  Island  of  Desolation  !  The  numbers  of  the 
fur-seals  killed  in  the  South  Shetland  Isles  (S.  lat. 
63°,)  in  1821  and  1822,  amounted  to  three  hundred 
and  twenty  thousand.  This  valuable  animal  is  now 
almost  extinct  in  all  these  islands."  From  the  most 
authentic  statements  it  appears  certain  that  the  fur 
trade  must  henceforward  decline,  since  the  advanced 
state  of  geographical  science  shows  that  no  new 
countries  remain  to  be  explored.  In  North  America 
the  animals  are  slowly  decreasing  from  the  perse- 
vering efforts,  and  the  indiscriminate  slaughter, 
practised  by  the  hunters,  and  by  the  appropriation 
to  the  use  of  man,  of  those  forests  and  rivers  which 
once  afforded  them  food  and  protection.  They 
recede  with  the  aborigines  before  the  tide  of  civi- 
lization. 

4.  THE  AFTERYX  AUSTRALIS.  —  An  extra- 
ordinary bird,  a  native  of  New  Zealand,  of  which 
but  few  living  individuals  are  known  to  naturalists, 
appears  to  be  on  the  point  of  extinction  ;  it  is  the 


118  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

Apteryx  Australia,  so  called  from  being  destitute  of 
wings.  The  only  known  specimen  was  figured  and 
described  by  Dr.  Shaw,  and  is  now  in  the  collection 
of  Lord  Stanley.  It  has  lately  been  examined  by 


TAB.  16.— APTERYX  ACSTRALIS. 

Mr.  Yarrell,  by  whom  the  characters  of  the  skeleton 
have  been  correctly  ascertained.  This  bird  is  of  a 
greyish  brown  colour,  and  has  neither  wings  nor 
tail.  The  beak  is  slightly  curved,  and  the  nasal 
apertures,  instead  of  opening  at  the  base,  as  in  birds 
in  general,  and  especially  in  those  of  a  similar  con- 
formation of  beak,  which  is  adapted  for  respiration 
while  immersed  in  mud  or  water,  is  placed  at  the 
apex.  The  eyes  are  very  small.  The  feathers  are 
long  and  loose,  like  those  of  the  emu,  but  each 
plume  has  only  a  single  shaft.* 

•  Since  the  former  edition  of  this  work,  three  or  four  dead 
specimens  of  the  apteryx  have  been  brought  from  New  Zealand 
to  this  country.  Mr.  Gould  states  that  it  is  a  very  rare  bird, 
and  that  its  nocturnal  habits  render  it  difficult  to  be  obtained. 
Its  skin  is  in  much  request  among  the  New  Zealand  chiefs,  to 


§5.  THE  DODO.  119 

5.  THE  DODO  (Didus  ineptus). — A  remarkable 
instance  of  the  extirpation  of  a  peculiar  type  of 
organization  is  afforded  by  the  dodo,  which  has 
been  annihilated,  and  become  a  denizen  of  the  fossil 
kingdom,  almost  before  our  eyes.  The  dodo  was 
a  bird  of  the  gallinaceous  tribe,  larger  than  a 
turkey,  which  abounded  in  the  Mauritius  and  ad- 
jacent islands,  when  those  countries  were  first 


TAB.  17. — THE  DODO. 

colonized  by  the  Dutch,  about  two  centuries  ago. 
This  bird  formed  the  principal  food  of  the  in- 
habitants, but  it  was  found  to  be  incapable  of  do- 
mestication, and  its  numbers  therefore  soon  became 

ornament  their  war  dresses.  Captain  Syraonds  also  mentions 
the  apteryx  as  frequenting  Cloudy  Bay,  and  affording  excellent 
sport  to  the  hunters,  to  whom  it  is  of  great  value,  on  account 
of  its  feathers,  which  are  held  in  high  estimation  among  the 
natives. 


120  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

sensibly  diminished.  Scuffed  specimens  were  pre- 
served in  the  museums  of  Europe,  and  paintings 
of  the  living  animal  are  still  extant  in  the  Ash- 
molean  Museum  at  Oxford,  and  in  the  British 
Museum.  But  the  dodo  is  now  extinct  —  it  is 
no  longer  to  be  found  in  the  isles  where  it  once 
flourished  ;  and  even  all  the  stuffed  specimens  are 
destroyed.  The  only  relics  that  remain,  are  the 
head  and  foot  of  an  individual  in  the  Ashmolean, 
and  the  leg  of  another  in  the  British  Museum.  To 
render  this  illustration  complete,  the  bones  of  the 
dodo  have  been  found  in  a  tufaceous  deposit,  be- 
neath a  bed  of  lava,  in  the  Isle  of  France ;  so  that 
if  the  remains  of  the  recent  bird  already  alluded  to, 
had  not  been  preserved,  these  fossil  relics  would 
have  constituted  the  only  proof  that  such  a  creature 
had  ever  existed  on  our  planet. 

6.  THE  IRISH  ELK,  or  CERVUS  MEGACEROS. 
(elk  with  great  antlers.) — The  shell  marls  of  Ireland 
also  afford  evidence  of  the  existence  of  an  animal, 
which,  like  the  dodo,  was  once  cotemporaneous 
with  the  human  species,  but  is  now  altogether 
extinct,  the  last  individual  of  the  race  having,  in 
all  probability,  been  destroyed  by  man.  Its  re- 
mains commonly  occur  in  the  beds  of  marl  beneath 
the  peat-bogs,  which  are  apparently,  like  those  of 
Scotland,  the  sites  of  ancient  lakes.  In  Curragh, 
immense  quantities  of  the  bones  of  the  elk  lie  within 
a  small  space,  as  if  the  animals  had  assembled  in  a 
herd :  the  skeletons  appear  to  be  entire,  and  the 


§  6.  THE  IRISH  ELK.  121 

nose  is  elevated,  the  antlers  being  thrown  back  on 
the  shoulders,   as  if  the   creatures  had  sunk  in  a 
morass,  and  been  suffocated.      Remains  of  the  elk 
occur  also  in  marl  and  gravel,  in  many  parts  of  Eng- 
land, France,  Germany,  and  Italy.     This  enormous 
ruminant  very  far  exceeded  in  magnitude  any  living 
species.     The  skeleton  is  upwards  of  ten  feet  high 
from  the  ground  to  the  highest  point  of  the  antlers, 
which  are  palmated,  and  are  from  ten  to  fourteen 
feet  from  one  extremity  to  the  other.    The  museum 
of  the   late  eminent   anatomist,   Joshua    Brookes, 
which,  to  the  disgrace  of  the  government  of  this 
country,  was  suffered  to  be  dispersed,  contained  a 
magnificent  pair,  measuring  eleven  feet  in  expanse, 
which  are  now  in  my  collection.     Skulls  have  been 
found  without  horns,  and  these  probably  belonged 
to  females.     The  average  weight  of  the  skull  and 
antlers  is  computed  at  three  quarters  of  a  hundred- 
weight ;  they  are  generally  in  a  fine  state  of  preser- 
vation, of  a  dark  brown  colour,  with  here  and  there 
a  bluish  incrustation  of  phosphate  of  iron,  like  those 
of  the  deer  from  Lewes  Levels.      The  elk  shed  its 
horns,  and  probably,  like  existing  species,  annually. 
Professor  Jameson,  Mr.  Weaver,  and  others,  have 
clearly  proved  that  this  majestic  creature  was  coeval 
with  man.     A  skull  was  discovered  in  Germany, 
associated  with  urns  and  stone  hatchets ;   and  in 
the  county  of  Cork,  a  human  body  was  exhumed 
from  a  wet  and  marshy  soil,  beneath  a  bed  of  peat 
eleven  feet  thick;   the  body  was  in  good  preser- 


122  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

ration,  and  enveloped  m  a  deer  skin  covered  with 
hair,  which  there  is  every  reason  to  conclude  was 
that  of  the  elk.  A  rib  of  the  elk  has  also  been 
found,  in  which  there  is  a  perforation,  that  evidently 
had  been  formed  by  a  pointed  instrument  while  the 
animal  was  alive,  for  there  is  an  effusion  of  callus 
or  new  bony  matter,  which  could  only  have  resulted 
from  something  remaining  in  the  wound  for  a  con- 
siderable period  ;  such  an  effect,  indeed,  as  would 
be  produced  by  the  head  of  an  arrow  or  spear.* 
There  is,  therefore,  presumptive  evidence  that  the 
race  was  extirpated  by  the  hunter-tribes  who  first 
took  possession  of  these  islands. 

Beds  of  gravel  and  sand,  containing  recent  marine 
shells  and  bones  of  the  Irish  elk,  have  been  ob- 
served by  Dr.  Scouler  in  the  vicinity  of  Dublin,  at 
an  elevation  of  two  hundred  feet  above  the  level  of 
the  sea.  It  is  therefore  manifest  that  this  extinct 
quadruped,  although  found  in  peat-bogs  and  mo- 
rasses at  a  comparatively  recent  period,  must  have 
been  an  inhabitant  of  Ireland  antecedently  to  some 
of  the  last  changes  in  the  relative  position  of  the 
land  and  water.  The  discovery  of  a  vast  number 
of  skeletons  of  the  elk  in  the  small  area  of  the  Isle 
of  Man,  seems  to  indicate  a  great  alteration  in 
the  extent  of  land  and  sea ;  for  it  is  difficult  to 
conceive  that  such  herds  of  this  gigantic  race  could 
exist  in  so  limited  a  district ;  and  it  is  therefore 
probable  that  the  island  was  separated  from  the 
*  Jameson's  Cuvier. 


§  7,8.  EPOCH  OF  GIGANTIC  MAMMALIA.  123 

main  land  at  no  remote  geological  period,  by  subsi- 
dences commensurate  with  the  elevation  of  which 
Ireland  affords  such  decisive  evidence.* 

In  the  remarkable  examples  just  cited,  we  have 
an  interesting  transition  from  the  recent  to  the  lost 
types  of  animal  existence.  1st,  Species  extinct  in 
the  British  islands,  but  still  living  in  other  coun- 
tries. 2dly,  Animals  which  have  been  entirely 
destroyed  within  the  last  few  centuries.  Lastly, 
Species  that  were  blotted  out  from  the  face  of  the 
earth  by  the  early  races  of  mankind. 

7.    EPOCH    OF    TERRESTRIAL    MAMMALIA. We 

must  now  advance  another  step  in  the  history  of 
the  past,  and  proceed  from  the  consideration  of 
what  is  known,  to  that  which  is  unknown  ;  the  sub- 
sequent divisions  of  this  discourse  will  be  restricted 
to  the  geological  phenomena  of  the  period  imme- 
diately antecedent  to  the  present ;  a  period  in  which 
the  earth  appears  to  have  teemed  with  enormous 
mammalia,  and  with  which  but  few  species  of  the 
existing  races  were  associated.  Thus  while  the 
present  may  be  termed  the  modern  or  human 
epoch,  that  which  forms  the  immediate  subject  of 
our  investigation  may  be  designated  the  epoch  of 
gigantic  mammalia* 

8.  CHARACTER  OF  THE  ANCIENT  ALLUVIAL 
DEPOSITS. — "  When  the  traveller,"  says  Cuvier, 
"  passes  over  those  fertile  plains,  where  the  peaceful 

*  Address  of  Charles  Lyell,  Esq.  President  of  the  Geological 
Society  of  London,  1837. 


124  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

waters  preserve,  by  their  regular  courses,  an  abun- 
dant vegetation,  and  the  soil  of  which  is  crowded  by 
an  extensive  population,  and  enriched  by  flourishing 
cities,  which  are  never  disturbed  but  by  the  ravages 
of  war,  or  the  oppression  of  despotism,  he  is  not 
inclined  to  believe  that  nature  has  also  had  her 
intestine  wars,  and  that  the  surface  of  the  globe  has 
been  overthrown  by  various  revolutions  and  cata- 
strophes. But  his  opinions  change  as  he  penetrates 
into  that  soil  at  present  so  peaceful ;  or  as  he  ascends 
the  hills  which  bound  the  plains.  His  ideas  expand, 
as  it  were,  with  the  prospect;  and  so  soon  as  he 
as-cends  the  more  elevated  chains,  or  follows  the  beds 
of  those  torrents  which  descend  from  their  summits, 
he  begins  to  comprehend  the  extent  and  grandeur 
of  those  physical  events  of  ages  long  past.  Or  if 
he  examine  the  quarries  on  the  sides  of  the  hills,  or 
the  cliffs  which  form  the  boundaries  of  the  ocean, 
he  there  sees,  in  the  displacement  and  contortion  of 
the  strata,  and  in  the  layers  of  water-worn  materials, 
teeming  with  the  remains  of  animals  and  plants, 
proofs  that  those  tranquil  plains,  those  smooth  un- 
broken downs,  have  once  been  at  the  bottom  of  the 
deep,  and  have  been  lifted  up  from  the  bosom  of 
the  waters;  and  everywhere  he  will  find  evidence 
that  the  sea  and  the"  land  have  continually  changed 
their  place." 

In  almost  every  part  of  the  world,  beneath  the 
modern  alluvial  soil,  the  nature  and  character  of 
which  were  described  in  the  former  lecture,  exten- 


§9.  CLASSIFICATION  OF  MAMMALIAN  REMAINS.        125 

sive  beds  of  gravel,  clay,  and  loam,  are  found  spread 
over  the  plains,  or  on  the  flanks  of  the  mountain 
chains,  or  on  the  crests  of  ranges  of  low  elevation  ; 
and  in  these  accumulations  of  water-worn  mate- 
rials, are  immense  quantities  of  the  bones  of  large 
mammalia.*  These  remains  belong  principally  to 
animals  related  to  the  elephant,  as  the  mammoth, 
mastodon,  &c.,  and  to  various  species  of  hippopo- 
tamus, rhinoceros,  horse,  ox,  deer,  and  many  of 
extinct  genera  ;  while  in  caverns  and  fissures  of 
rocks  filled  with  calcareous  breccia,  the  skeletons 
of  tigers,  boars,  hyenas,  and  other  carnivorous  ani- 
mals, are  imbedded.  Fossil  bones  of  this  kind 
exist,  in  such  abundance,  all  over  Europe,  Asia, 
and  America,  that  it  is  impossible  to  enumerate 
the  localities ;  they  are  found  alike  in  the  tropical 
plains  of  India,  and  in  the  frozen  regions  of  Siberia ; 
while  there  is  no  considerable  district  of  Great 
Britain  in  which  some  traces  of  these  remains  do 
not  occur. 

9.  CLASSIFICATION  OF  MAMMALIAN  REMAINS. 
— Dr.  Buckland  considers  these  remains  as  refer- 
able to  four  divisions. 

First.  Land  animals,  drifted  into  estuaries  or  seas, 
and  associated  with  marine  shells,  such  as  those 
found  in  the  Sub-Apennine  formations  ;  in  the  beds 
of  gravel,  sand,  &c.  provincially  termed  crag,  in 

*  The  term  diluvium  is  commonly  applied  to  these  ancient 
alluvial  beds ;  they  are  the  newer  pliocene  in  the  classification 
of  Mr.  Lyell,  as  we  shall  hereafter  explain. 


126  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

Norfolk  and  Suffolk ;  loam  and  chalk  conglomerate 
in  Brighton  cliffs  ;  and  in  clay  off  Harwich  and 
Herne  Bay,  and  on  the  coast  of  Western  Sussex. 

Secondly.  Terrestrial  quadrupeds,  imbedded  with 
fresh-water  shells ;  in  strata  that  have  been  formed 
during  the  same  epoch  as  the  above,  at  the  bottom 
of  fresh-water  lakes ;  such  are  the  fossil  bones  of 
the  lacustrine  marls  of  the  Val  d' Arno. 

Thirdly.  Similar  remains  in  superficial  detritus, 
spread  over  the  surface  of  rocks  of  all  ages ;  as  in 
beds  of  gravel  near  London  ;  Petteridge  Common, 
Surrey  ;  near  Eastbourn,  Sussex,  &c. 

Fourthly.  Osseous  remains  of  carnivorous  and 
herbivorous  animals  in  caverns  and  fissures  of  rocks 
which  formed  part  of  the  dry  land,  during  the  later 
period  of  the  same  epoch.  The  caverns  of  Gaylen- 
reuth,  Kirkdale,  &c.  are  examples. 

Lastly.  The  relics  in  the  osseous  breccias  that 
occur  in  fissures  of  limestone  on  the  shores  of  the 
Mediterranean,  in  the  Ionian  Isles,  in  the  rock  of 
Gibraltar,  at  Plymouth,  and  in  the  Mendip  hills.* 

Before  I  direct  your  attention  to  the  fossils  before 
us,  which  have  been  collected  from  the  alluvial  de- 
posits under  examination,  and  from  various  local- 
ities, it  will  be  necessary  to  review  the  leading 
principles  of  that  science  which  explains  the  struc- 
ture of  animal  existence.  Thus  while  in  our  pre- 
ceding investigations  we  referred  to  Astronomy  to 
dissipate  the  obscurity  which  shrouded  the  earliest 
*  Dr.  Buckland's  Bridgwater  Essay,  p.  94. 


§  10.  COMPARATIVE  ANATOMY.  127 

history  of  our  planet,  we  are  now  led  to  that  impor- 
tant department  of  natural  knowledge,  Comparative 
Anatomy,  to  enable  us  to  restore  the  lost  forms  of 
animal  existence.  I  shall  therefore  explain  the 
mode  of  induction  employed  by  the  scientific  ob- 
server, in  his  investigation  of  the  fossil  remains  of 
animals,  by  which  he  is  enabled  to  ascertain  the 
structure  and  habits  of  those  creatures  which  have 
long  since  disappeared  from  the  face  of  the 
earth. 

10.  COMPARATIVE  ANATOMY.  —  To  a  person 
uninstructed  in  this  science,  the  specimens  before 
us  would  appear  a  confused  medley  of  bones  and 
of  osseous  fragments,  impacted  in  solid  stone ;  and 
the  only  knowledge  he  could  derive  from  their  ex- 
amination would  be  the  fact,  that  the  stone  was 
once  in  the  state  of  sand  or  mud,  in  which,  while 
soft,  the  bones  had  become  imbedded.  But  in  vain 
would  he  seek  for  further  information  from  these 
precious  historical  monuments  of  Nature ;  to  him 
they  would  appear  as  unintelligible  as  were  the 
hieroglyphics  of  Egypt,  before  Young  and  Cham- 
pollion  explained  their  mysterious  import.  It  is 
only  by  an  acquaintance  with  the  structure  of  the 
living  forms  around  us,  and  by  acquiring  an  inti- 
mate knowledge  of  their  osseous  frame-work  or 
skeleton,  that  we  can  hope  to  decipher  the  hand- 
writing on  the  rock,  obtain  a  clue  to  guide  us 
through  the  labyrinth  of  fossil  anatomy,  and  con- 
duct to  those  interesting  results,  which  the  genius 


128  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

of  the  immortal  Cuvier  first  taught  us  how  to 
acquire.  And  here  it  will  be  necessary  to  enter 
upon  the  consideration  of  those  beautiful  principles 
of  the  co-relation  of  structure  in  organized  beings, 
which  were  first  announced  by  that  illustrious  phi- 
losopher. 

11.  ADAPTATION  OF  STRUCTURE  IN  ANIMALS. 
— The  organs  of  every  animal,  observes  M.  Cuvier, 
may  be  considered  as  forming  a  machine,  the  parts 
of  which  are  mutually  dependent  on  each  other, 
and  exquisitely  adapted  for  the  functions  they  are 
destined  to  perform ;  and  such  is  the  intimate  rela- 
tion of  the  several  organs,  that  any  variation  in  one 
part,  is  constantly  accompanied  by  a  corresponding 
modification  in  another.  This  mutual  adaptation 
of  the  several  parts  of  the  animal  fabric  is  a  law  of 
organic  structure,  which,  like  every  other  induction 
of  physical  truth,  has  only  been  established  by 
patient  and  laborious  investigation.  It  is  by  the 
knowledge  of  this  law  that  we  are  enabled  to  re- 
assemble, as  it  were,  the  scattered  remains  of  the 
beings  of  a  former  state  of  the  globe, — to  determine 
their  place  in  the  scale  of  animated  nature, — and 
to  reason  on  their  structure,  habits,  and  economy, 
with  as  much  clearness  and  certainty,  as  if  they 
were  still  living  and  before  us.  I  will  demonstrate 
this  proposition  by  a  few  examples.  Of  all  the  solid 
parts  of  the  animal  structure  the  most  obviously 
mechanical  are  the  jaws  and  teeth  ;  and  as  we  know 
in  each  instance  the  operations  they  are  intended  to 


§  12.        OSTEOLOGICAL  CHARACTER  OF  CARNIVORA.        129 

perform,  they  afford  the  most  simple  and  striking 
illustration  of  the  principles  above  enunciated. 


TAB.  18. — SKULL  OF  THE  BENGAL  TIGER. 

12.  OSTEOLOGICAL  CHARACTERS  OF  THE  CAR- 
NIVORA.— If  we  examine  the  jaws  of  the  skulls 
before  us,  those  of  a  Bengal  tiger,  and  of  a  cat,  we 
perceive  that  there  are  cutting  teeth  in  front, — 
sharp  fangs  on  the  sides, — and  molar,  bruising,  or 
crushing  teeth,  in  the  back  part.  The  molar  rise 
into  sharp  lanciform  points,  and  over-lap  each  other 
in  the  upper  and  lower  jaw,  like  the  edges  of  a  pair 
of  shears ;  and  the  teeth  are  externally  covered 
with  a  thick  crust  of  enamel.  This  is  evidently 
an  apparatus  for  tearing  and  cutting  flesh,  or  for 
cracking  bones ;  but  is  not  suited  for  grinding  the 
stalks  or  seeds  of  vegetables.  The  jaws  fit  together 
by  a  transverse  process,  which  moves  in  a  corre- 
sponding depression  in  the  skull,  like  a  hinge 
(Tab.  18) ;  they  open  and  shut  like  shears,  but 
admit  of  no  grinding  motion  ;  this,  then,  is  such  an 
articulation  as  is  adapted  for  a  carnivorous  animal ; 
and  every  part  of  this  instrument  is  admirably 
fitted  for  its  office. 

K 


130  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

But  all  these  inimitable  adjustments  would  be 
lost,  were  there  not  levers  and  muscles  to  work  the 


TAB.  19. — SKULL  OF  A  WILD  CAT. 
(Felis  Canadensis.) 

jaws, — were  not  each  portion  of  the  animal  frame 
adapted  to  all  the  other  parts, — and  were  not  the 
instincts  and  appetites  of  the  animal  such  as  are 
calculated  to  give  to  this  apparatus  its  appropriate, 
movements.  Let  us  reverse  the  order  of  the  argu- 
ment,— let  us  assume  that  the  stomach  of  an  animal 
be  so  organized  as  to  be  fitted  for  the  digestion  of 
flesh  only,  and  that  flesh  recent, — we  should  find 
that  its  jaws  would  be  so  constructed  as  to  fit  them 
for  devouring  live  prey, — the  claws  for  seizing  and 
tearing  it, — the  teeth  for  cutting  and  dividing  it, — 
the  whole  system  of  its  powers  of  motion  for  pur- 
suing and  overtaking  it, — the  organs  of  sense  for 
discovering  it  at  a  distance, — and  the  brain  endowed 
with  the  instinct  necessary  for  teaching  the  animal 
how  to  conceal  itself,  and  lay  snares  for  its  victims. 


§  13.  STRUCTURE  OF  THE  HERBIVORA.  131 

Such  are  the  general  relations  of  the  structure  of 
carnivorous  animals,  and  which  every  being  of  this 
class  must  indispensably  combine  in  its  constitution, 
or  its  race  cannot  exist.  But  subordinate  to  these 
principles,  are  others  connected  with  the  nature 
and  habits  of  the  prey  upon  which  the  animal  is 
intended  to  subsist,  and  thence  result  modifications 
of  the  details  in  the  forms  which  arise  from  the 
general  conditions.  Thus,  in  order  that  the  animal 
may  have  the  power  requisite  to  carry  off  its  prey, 
there  must  be  a  certain  degree  of  vigour  in  the 
muscles  which  elevate  the  head ;  and  thence  results 
a  determinate  form  in  the  vertebrae  or  bones  from 
which  these  muscles  originate,  and  in  the  back  of 
the  head  in  which  they  are  inserted.  That  the 
paws  may  be  able  to  seize  their  prey,  there  must  be 
a  certain  degree  of  mobility  in  the  toes,  and  of 
strength  in  the  claws,  and  a  corresponding  form  in 
all  the  bones  and  muscles  of  the  foot.  It  is  un- 
necessary to  extend  these  remarks,  for  it  will  easily 
be  seen  that  similar  conclusions  may  be  drawn  with 
regard  to  all  the  other  parts  of  the  animal.*  In 
the  tiger  and  the  cat  we  have  a  familiar  illustration 
of  what  has  been  advanced. 

13.  STRUCTURE  OF  THE  HERBIVORA.  —  In 
animals  which  are  destined  to  live  on  vegetables  we 
have  the  same  mutual  relations ;  the  sharp  fangs  of 
the  teeth  are  wanting,  the  enamel  is  not  all  placed 

*  Consult  Cuvier's  "  Theorie  de  la  Terre ;"  "  Le9ons  d' Ana- 
tomic Comparative ;"  "  Ossemens  Fossiles;"  &c. 
K    2 


132  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

on  the  top  of  the  teeth  as  in  the  carnivora,  but 
arranged  in  deep  vertical  layers,  alternating  with 
bony  matter;  and  this  arrangement,  in  all  states 
of  the  teeth,  secures  a  rough  grinding  surface,  as  in 
the  horse  and  the  elephant.  The  flat  molar  teeth 


TAB.  20.— SKULL  OF  THJS  HORSE. 

are  not  formed  for  cutting,  but  for  mastication, 
and  the  jaws  are  loosely  articulated  together  so  as 
to  allow  of  a  grinding  movement :  had  the  socket 
and  corresponding  part  of  the  jaw  been  the  same 
as  in  the  tiger,  the  tooth  could  not  have  performed 
its  office.  Again,  I  might  proceed  in  the  argu- 
ment, and  show  the  adaptation  of  the  muscles  of 
the  head  to  the  apparatus  here  described;  and 
beginning  with  the  jaw,  review  the  whole  animal 
frame,  and  demonstrate  how  all  its  parts  are  alike 
wonderfully  constructed  and  fitted  together,  to 
perform  the  functions  necessary  for  the  being  to 
which  it  belongs. 


§14. 


STRUCTURE  OF  THE  RODENTIA. 


133 


14.  STRUCTURE  OF  THE  RODENTIA,  OR  GNAW- 
ERS.—  In  the  jaws  of  an  intermediate  order  of 
animals,  we  find  new  modifications  of  the  same 


TAB.  21.— SKULI  AND  TEETH  OF  RODENTIA,  on  GNAWERS. 

Fig.  1.  Molar  teeth  of  the  upper  jaw  of  a  Florida  rat  (Arvicola  Floridana) 
magnified;  seen  obliquely.  Fig.  2.  Left  side  of  the  lower  jaw,  of  the 
natural  size.  Fig.  3.  Skull  of  the  squirrel. 

apparatus.  Thus  the  rodentia,  or  gnawers,  have 
long  sharp  cutting  teeth,  like  nippers ;  it  is  by  these 
that  the  rat  can  very  speedily  gnaw  a  hole  through 
a  board,  and  the  squirrel  in  a  nut,  in  consequence 
of  their  exquisite  adaptation  for  these  operations. 
In  the  skull  of  the  squirrel  (Tab.  21,  fig.  3)  the 


134  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

front  teeth  are  of  enormous  size,  as  compared  with 
the  molar,  and  they  lock  together  in  such  manner 
as  to  render  a  grinding  movement  impossible ;  a 
new  adjustment  has,  therefore,  been  supplied, — the 
lower  jaw  is  so  adapted  as  to  work  in  the  skull 
neither  in  a  transverse  nor  in  a  rotatory  direction, 
but  lengthwise,  like  the  action  of  a  carpenter  using 
his  plane,  the  teeth  moving  backwards  and  forwards, 
as  may  be  observed  in  the  rabbit  while  eating  its 
food.  The  enamel  of  the  molar  teeth  (see  Tab.  21, 
fig.  1)  is  placed  vertically  and  transverse  to  the 
jaw,  so  as  to  form  an  admirable  grinding  surface. 
But  this  is  not  the  only  variation  of  structure  ob- 
servable in  the  teeth  of  these  animals.  The  incisors 
being  implements  of  constant  use,  are  renewed  by 
continual  growth,  and  there  is  a  special  provision 
for  their  support  in  a  bent  socket.  The  enamel  is 
unequally  distributed  round  the  tooth,  being  very 
thin  behind  and  thick  in  front,  by  which  means  the 
cutting  edges  are  always  preserved;  for  by  the  very 
act  of  gnawing,  the  hinder  part  of  the  incisor  wears 
away  quicker  than  the  fore  part,  and  thus  a  sharp 
inclined  edge,  like  that  of  an  adze  or  chisel,  is 
maintained,  and  which  is  the  very  form  required 
in  the  economy  of  the  animal.  The  skull  of  the 
common  rabbit  or  hare  will  exemplify  these  re- 
marks. 

15.  GENERAL  INFERENCES.  —  These  are  but  a 
few  examples  of  those  admirable  adaptations  of 
means  to  ends  which  are  observable  throughout 


§  15.  GENERAL  INFERENCES.  135 

the  various  classes  of  organized  beings :  but  the 
limits  of  a  single  lecture  will  not  allow  me  to  be 
more  diffuse,  and  I  trust  it  is  unnecessary  to  offer 
further  remarks,  to  show  that  the  conclusions  of 
geologists,  as  to  the  ancient  inhabitants  of  our 
globe,  are  not  vague  assumptions,  as  those  unac- 
quainted with  the  science  might  suppose,  but  the 
legitimate  deductions  of  laborious  and  patient  in- 
vestigations. A  few  teeth  and  bones — sometimes 
but  a  single  relic  of  this  kind — are  the  elements 
by  which  the  comparative  anatomist  is  enabled, 
not  only  to  restore  the  forms  of  creatures  now 
banished  from  the  face  of  the  earth,  but  also  to 
ascertain  their  habits  and  economy,  and  even  arrive 
at  positive  conclusions  respecting  the  nature  of  the 
country  of  which  they  were  once  the  inhabitants. 
If  we  find  the  remains  of  animals  which  lived  on 
vegetables,  it  follows  that  there  must  have  been 
vegetables  for  their  subsistence,  and  a  condition  of 
nature  calculated  for  the  growth  of  vegetable  pro- 
ductions; a  soil  fitted  for  their  existence,  and  a 
country  diversified  by  hills,  valleys,  and  plains, 
with  streams  and  rivers  to  carry  off  its  superfluous 
waters.  The  same  laws,  under  certain  modifica- 
tions, apply  to  other  classes  of  beings.  In  birds,  the 
form  of  the  feet  is  modified  according  to  the  habits 
of  the  different  orders.  In  the  parrot,  (Tab.  22, 
fig.  3,)  the  claws  are  adapted  to  climb  trees  and 
perch  on  the  branches;  but  in  the  eagle  they  are 
widely  different,  for  its  talons  are  constructed  to 


136 


THE  WONDERS  OF  GEOLOGY. 


LECT.  II. 


lacerate  and  tear  its  prey,  (Fig.  4.)     The  feet  of 
aquatic  birds  are  formed  like  a  paddle  or  oar,  to 


TAB.  22.— DIFFERENT  FORMS  OF  FEET  IN  BIRHS. 

Fig.  1.  Foot  of  the  heron ;  Fig.  2.  Of  the  ostrich ;  Fig.  3.  Of  the  parrot; 
Fig.  4.  Of  the  eagle  ;   Fig.  5.  Of  the  pelican. 

enable  them  to  make  their  way  through  the  water 
(Fig.  5) ;  those  of  birds  that  frequent  marshes  have 
a  great  expansion,  like  a  tripod,  that  they  may  move 
over  the  unstable  surface  of  the  morass  (Fig.  1); 
while  in  species  destined  to  inhabit  sandy  deserts,  as 
the  ostrich  (Fig.  2),  the  feet  present  a  corresponding 
change  of  structure. 

We  perceive,  therefore,  that  every  vertebrated 
animal  has  a  solid  and  durable  skeleton,  or  osseous 


§  16.  FOSSIL  BONES.  137 

support,  formed  upon  one  general  plan,  but  modified 
in  almost  endless  variety,  in  the  relative  magnitude, 
situation,  and  aspect  of  the  different  parts,  so  as  to 
adapt  itself  to  the  various  habits  and  functions  of 
the  diversified  forms  of  animal  life.  In  short,  that 
the  Author  of  nature  has  by  these  changes  varied 
the  same  general  fabric  in  innumerable  ways ;  be- 
stowed upon  it  a  thousand  different  instincts  and 
passions ;  adapted  it  to  every  element  and  climate ; 
and  to  every  possible  variety  of  food  and  mode  of 
existence. 

From  a  knowledge  of  these  principles  of  the  co- 
relation  of  the  different  parts  of  every  organized 
being,  which  I  have  thus  attempted  to  explain,  we 
may  understand  how  the  scientific  observer  can 
reconstruct  the  entire  animal  fabric:  and  we  are 
now  prepared  to  enter  upon  that  department  of 
geology  called  Palaeontology ,  or  the  science  which 
relates  to  the  fossil  remains  of  the  beings  which 
inhabited  our  planet  in  former  ages. 

16.  FOSSIL  BONES. — As  the  bones  are  the  least 
perishable  parts  of  the  animal  structure,  they  be- 
come the  most  frequent,  and  often  the  only  indica- 
tions of  the  zoological  characters  of  the  more  ancient 
epochs.  Occasionally  very  delicate  parts,  such  as 
the  tunic  of  the  eye,  the  membranes  of  the  stomach, 
and  the  wings  of  insects,  are  preserved  in  a  fossil 
state,  examples  of  which  we  shall  hereafter  adduce. 
In  the  older  rocks,  the  bones  are  generally  mineral- 
ized, and  no  longer  possess  the  white  and  glossy 


138  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

appearance  of  the  recent  skeleton  ;  but  those  which 
occur  in  the  superficial  gravel,  and  in  caverns,  are 
commonly  of  a  porous  and  earthy  character,  like 
bones  that  have  lost  a  portion  of  their  animal 
matter  by  being  buried  in  a  dry  and  loose  soil. 

The  animals  whose  fossil  remains  I  now  proceed 
to  describe,  may  be  separated  into  two  classes — the 
HERBIVORA,  whose  bones  occur  in  the  gravel  and 
marl, — and  the  CARNIVORA,  which  are  found  in 
fissures  and  caverns. 

17.  FOSSIL  ELEPHANTS,  Or  MAMMOTHS.* 1  will 

first  notice  the  fossil  remains  of  the  animals  of  the 
elephantine  family,  which  occur  in  great  abun- 
dance, and  are  very  generally  distributed.  In  the 
earlier  ages,  these  colossal  bones  were  supposed  to 
belong  to  gigantic  races  of  mankind,  and  hence 
the  tradition  of  giants  possessed  by  every  country 
in  Europe :  nor  need  we  smile  at  the  ignorance  and 
credulity  of  our  ancestors,  for,  not  many  years  since, 
a  fossil  tooth  of  an  elephant,  which  was  discovered 
in  digging  a  well  in  Brighton,  was  supposed  to  be  a 
petrified  cauliflower ! — In  Russia,  and  more  parti- 
cularly in  Siberia,  the  fossil  bones  of  elephants  are 
found  throughout  all  the  low  lands,  and  in  the  sandy 
plains,  but  not  in  the  elevated  primary  chain  of 
hills,  stretching  from  the  borders  of  Europe  to 
the  nearest  extreme  point  of  America,  and  south 
and  north  from  the  base  of  the  mountains  of 
central  Asia,  to  the  shores  of  the  Arctic  sea. 
*  From  the  Arabic  behemoth,  signifying  elephant. 


§  IS.  FOSSIL  ELEPHANTS,  OR  MAMMOTHS.  139 

Within  this  space,  which  is  almost  equal  in  extent 
to  the  whole  of  Europe,  fossil  ivory  is  everywhere 
to  be  found;  and  the  tusks  are  so  numerous,  and 
well  preserved,  especially  in  Northern  Russia,  that 
thousands  are  annually  collected,  and  form  a  lucra- 
tive article  of  commerce.  In  Siberia  alone,  the 
remains  of  a  greater  number  of  elephants  have  been 
discovered,  than  are  supposed  to  exist  at  the  pre- 
sent time  all  over  the  world.  In  a  low  island  in 
the  Frozen  Sea  (72°  north  latitude)  bones  of  mam- 
moths are  seen  imbedded ;  and  they  also  abound  in 
an  iceberg  on  the  north-west  angle  of  the  American 
continent,  near  to  Behring's  Straits.  The  tur- 
quoises of  Simone  are  composed  of  mammoths' 
bones  impregnated  with  some  metallic  oxide. 

18.  MAMMOTH  AND  RHINOCEROS  IMBEDDED  IN 
ICE. — But  the  most  remarkable  fact  relating  to 
these  remains,  is  the  preservation,  not  merely  of 
the  bones,  but  of  entire  animals,  with  their  flesh 
and  skin,  in  ice-bergs  and  frozen  gravel !  In  1774-, 
near  Vilhoui,  the  carcase  of  a  rhinoceros  was  taken 
from  the  frozen  sand,  where  it  must  have  been 
concealed  for  ages,  the  soil  of  that  region  being 
always  frozen  to  within  a  few  inches  of  the  surface. 
The  carcase  was  a  complete  natural  mummy,  part 
of  the  skin  being  still  covered  with  long  hairs,  and 
forming  a  warmer  covering  than  that  of  the  African 
rhinoceros.  The  discovery  of  a  mammoth,  under 
similar  circumstances,  is  yet  more  interesting.  It 
appears,  that  towards  the  close  of  the  last  century, 


140  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

a  Tungusiari  fisherman  observed  in  a  cliff  of  ice  and 
gravel,  on  the  banks  of  the  river  Lena,  a  shapeless 
mass,  the  nature  of  which  he  was  unable  to  deter- 
mine. In  the  course  of  the  next  year  it  was  more 
visible,  and  on  the  third  a  large  tusk  was  seen 
projecting  from  the  ice-cliff,  and  at  length  became 
detached.  On  the  fifth  year,  an  early  thaw  set  in, 
and  the  entire  carcase  of  a  mammoth  was  exposed, 
and  at  length  fell  upon  the  ground.  It  was  twelve 
feet  high,  and  about  sixteen  feet  in  length;  the 
tusks  were  nine  feet  long.  The  flesh  was  in  such  a 
state  of  preservation,  that  it  was  devoured  as  it  lay 
by  wolves  and  bears,  and  the  hunters  fed  their  dogs 
with  the  remains.  The  skin  was  covered  with  hair 
consisting  of  black  bristles,  thicker  than  horsehair, 
and  fifteen  inches  in  length ;  of  wool  of  a  reddish 
brown,  and  hair  of  a  fawn  colour ;  and  with  a  mane 
on  the  neck.  Upwards  of  SOlbs.  of  hair  were  col- 
lected ;  specimens  of  which  may  be  seen  in  the 
Hunterian  museum,  of  the  College  of  Surgeons. 
The  ear  remained  dry  and  shrivelled ;  the  brain  and 
even  the  capsule  of  the  eye  were  preserved !  the 
bones  and  part  of  the  integuments,  and  a  consider- 
able quantity  of  the  hair,  are  in  the  Museum  of 
Natural  History  at  St.  Petersburgh.  The  accom- 
panying sketch  (Tab.  23)  represents  the  skeleton 
in  its  present  state. 

The  occurrence  of  large  mammalia,  in  latitudes 
where  but  few  forms  of  animal  life  can  now  possibly 
find  the  means  of  subsistence,  is  a  fact  of  so  much 


f  19.  MAMMOTH  IMBEDDED  IN  ICE.  141 

interest,  that  I  must  indulge  in  a  few  additional 
remarks.  The  existing  elephants  belong  to  two 
species,  namely,  the  African,  which  occurs  as  far 
south  as  the  Cape  of  Good  Hope,  and  the  Asiatic, 


TAB.  23. — MAMMOTH  FOUND  IMBEDDED  IN  FROZEN  GRAVEL  IN 

SIBERIA. 
(Twelve  feet  high,  and  sixteen  feet  long.) 

which  is  limited  to  31°  north  latitude.  They  are 
distinguished  by  certain  characters ;  but  those  which 
more  especially  relate  to  our  present  inquiry,  are 
the  peculiarities  of  the  teeth. 

19.  TEETH  OF  RECENT,  AND  FOSSIL  ELEPHANTS. 
— The  teeth  of  animals  are  formed  of  three  distinct 
substances,  which  are  variously  disposed  in  different 
orders,  according  to  the  habits  and  economy  of  the 
species ;  a  fact  to  which  I  alluded  when  treating  of 
the  anatomical  character  of  those  of  the  rodentia,  &c. 
The  nucleus  of  the  tooth  is  composed  of  a  bony 
matter,  consisting  almost  entirely  of  phosphate  of 


142 


THE  WONDERS  OF  GEOLOGY. 


LECT.  II. 


lime,  with  albumen,  and  gluten  ;  it  is  called  ivory. 
This  central  portion  of  the  tooth  is  covered  by  the 
enamel,  a  substance  which  is  still  more  dense,  and 
of  a  fibrous  structure,  and  so  hard  as  to  strike  fire 
with  steel.  In  human  teeth,  the  enamel  covers  the 
whole  external  surface,  and  the  ivory  forms  the 
internal  part.  In  herbivorous  animals  the  enamel 
and  ivory  are  intermixed ;  and  there  is  in  some 
genera,  a  third  substance  called  crusta  petrosa, 


TAB.  24. — TEETH  OF  RECENT  AND  FOSSIL  ELEPHANTS. 

Fig,  1 .  Fossil  tooth  of  an  elephant  from  Brighton  cliff,  partially  water-worn. 
Fig.  2.  Crown  of  a  tooth  of  the  African  elephant.  Fig.  3.  Grinding 
surface  of  a  tooth  of  the  mammoth,  or  fossil  elephant.  Fig.  4.  Grinding 
surface  of  the  Asiatic  elephant. 

which  is  a  kind  of  yellowish,  opaque  ivory.     These 
three  substances  enter  into  the  composition  of  the 


§  19.  TEETH  OP  ELEPHANTS.  143 

teeth  of  the  elephant,  and  their  intermixture  is 
apparent  on  the  masticating  surfaces ;  they  are  dif- 
ferently disposed  in  the  two  species.  In  the  African 
elephant  (Tab.  24,  fig.  2,)  the  worn  surface  of  the 
molar  teeth  presents  a  series  of  lozenge-shaped  lines 
of  enamel,  having  the  ivory  on  the  inner  margin 
of  the  ridges,  and  being  surrounded  by  the  crusta 
petrosa.  In  the  Asiatic  species  (fig.  4)  the  enamel 
forms  narrow  transverse  bands ;  and  the  tooth  of 
the  mammoth,  or  fossil  elephant,  (figs.  1  and  3,)  has 
an  analogous,  but  somewhat  different  distribution. 
It  is  obvious  that  the  structure  here  exhibited,  is 
fitted  for  the  grinding  of  vegetables  ;  for  the  three 
substances,  being  of  different  degrees  of  hardness, 
produce  by  their  unequal  wearing,  a  constant  rough 
surface  for  trituration.*  The  elephant  has  but  four 
teeth  in  each  jaw ;  the  deficiency  of  prehensile 
teeth  being  supplied  by  that  wonderful  organ,  the 
trunk.  The  teeth  found  in  a  fossil  state,  appear  to 
be  distinct  from  either  of  the  recent  species ;  but 
they  are  more  nearly  related  to  the  Indian  or  Asia- 
tic, than  to  the  African,  as  you  may  observe  by 
these  specimens  from  Siberia,  India,  North  Ame- 
rica, and  the  cliffs  on  the  Sussex  coast.  In  some 
examples  the  teeth  are  water- worn,  but  most  com- 
monly very  perfect,  and  exhibit  but  few  marks  of 
attrition.  From  a  careful  review  of  the  characters 
of  the  fossil  elephant,  or  mammoth  of  Siberia, 

*  See  Dr.  Roget's  Bridgwater  Treatise,  for  a  lucid  and  inte- 
resting Essay  on  the  teeth  of  various  animals. 


144  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

Cuvier  determined  th^t  the  species  was  now  ex- 
tinct; that  the  structure  of  the  teeth,  configuration 
of  the  skull,  and  the  hairy  and  woolly  skin,  proved 
that  it  was  adapted  to  live  in  a  colder  climate  than 
that  in  which  the  Asiatic  species  could  exist ;  and 
he  inferred  that  the  animals  originally  inhabited  the 
countries  where  their  remains  are  now  found  im- 
bedded ;  and  that  the  preservation  of  the  carcases 
in  ice,  showed  that  the  change  in  the  temperature 
of  the  climate  was  sudden,  and  has  since  remained 
unaltered. 

Mr.  Lyell  offers  an  ingenious  solution  of  this 
difficult  problem.  He  supposes  that  a  large  region 
of  central  Asia,  perhaps  the  southern  half  of  Siberia, 
may  have  enjoyed  a  climate  mild  enough  to  have 
admitted  of  the  existence  of  the  extinct  elephants, 
for  vegetation  may  be  found  in  lat.  40°  and  50° 
north ;  and  from  the  physical  geography  of  the 
country,  that  the  whole  tract  from  the  mountains 
to  the  sea  may  have  been  upraised  like  Sweden, 
and  the  refrigeration  of  the  north-east  of  Asia, 
and  its  present  physical  condition,  have  been  the 
result. 

My  limits  will  not  permit  me  to  dwell  at  length 
on  other  discoveries  of  fossil  elephants,  but  I  will 
notice  a  few  instances  in  our  own  country.  On  the 
coasts  of  Norfolk  and  Suffolk,  so  many  teeth  of 
elephants  have  been  collected,  that  the  late  Mr. 
Woodward  (author  of  "  The  Geology  of  Norfolk  ") 
calculated  that  they  must  have  belonged  to  above 


§  19.  TEETH  OF  ELEPHANTS.  145 

500  individuals.  At  Walton,  in  Essex,  and  at 
Herne  Bay,  bones  and  tusks  have  also  been  found. 
But  by  far  the  most  extraordinary  collection  of  the 
remains  of  British  fossil  elephants  that  I  ever  beheld, 
is  in  the  possession  of  Mr.  Gibson,  of  Bow,  near 
London;  it  comprises  skulls,  tusks,  and  teeth,  from 
the  sucking  animal  to  the  adult,  in  a  remarkable 
state  of  preservation  ;  the  whole  of  which  were 
discovered  in  Essex.  In  the  highly  interesting 
museum  of  W.  D.  Saull,  Esq.  of  London,  many  fine 
elephantine  remains  are  also  preserved.  On  the 
western  coast  of  Sussex,  and  in  the  neighbourhood 
of  Arundel,  Patcham,  and  Brighton,  teeth  and 
bones  of  elephants  have  at  different  times  been  ex- 
humed. At  Brighton  the  teeth  are  found  in  a 
deposit  of  water-worn  materials,  consisting  of  loam, 
chalk,  and  broken  flints,  resting  on  a  bed  of  shingle 
covering  the  chalk.*  In  the  conglomerate,  of 
which  I  have  already  spoken,  (Tab.  15,  p.  101,)  as 
well  as  in  the  superincumbent  deposit,  the  teeth 
of  elephants,  with  bones  and  teeth  of  a  species  of 
deer,  horse,  and  whale,  occur,  and  are  associated 
with  marine  shells.  When  these  remains  were 
imbedded,  this  part  of  the  English  coast  must  have 
joined  the  opposite  shores  of  France,  and  have 
formed  the  boundary  of  a  bay  or  estuary,  of  a 
country  inhabited  by  large  mammalia;  for  similar 
fossils  are  found  in  a  deposit  of  a  like  character, 
along  the  French  coast. 

*  See  Geology  of  the  South-East  of  England,  p.  32. 


146  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

20.  THE  MASTODON. — In  various  parts  of  North 
America,  there  are  marshy  tracts  abounding  in  salt 
or  brackish  waters,  which  are  frequented  by  deer, 
and  other  animals  ;  a  circumstance  from  which  they 
have  acquired  the  American  name  of  Lick.  In 
these  morasses  vast  quantities  of  bones  of  gigantic 
terrestrial  animals  have  been  discovered.  The 
spot  most  celebrated  for  these  remains  in  Kentucky, 
is  called  Big-bone  Lick,  and  is  situated  to  the 
south-east  of  the  Ohio,  in  the  midst  of  a  group  of 
low  hills,  and  is  traversed  by  a  small  stream  of 
brackish  water.  The  bottom  consists  of  a  black 


TAB.  25.  — TOOTH  OF  THE  GREAT  MASTODON,   FROM  THE  BANKS  OF 

THE  HUDSON;  WEIGHT  4lbs.* 
(From  Professor  Sllliman  of  Yale  College.) 

fetid  mud,  intermingled  with  sand,  and  vegetable 

matter ;  and  in  this  bog,  bones  of  great  magnitude 

*  The  drawing  is  one-third  of  the  diameter  of  the  original. 


§  20.  THE  MASTODON.  147 

occur  in  profusion.  Some  of  them  are  referable 
to  the  fossil  elephant,  but  others,  as  you  may 
observe  from  the  specimens  before  us,  must  have 
belonged  to  a  creature  not  less  gigantic,  but  with 
very  different  characters. 

These  teeth  are  composed  of  ivory  and  enamel  . 
only,  and  the  enamel,  which  is  very  thick,  is  spread 
over  the  crown  of  the  tooth,  which,  when  unworn,  '//. 
is  divided  into  several  transverse  tubercles,  or 
processes,  each  of  which  is  subdivided  into  two 
obtuse  points ;  from  this  character  of  the  teeth 
the  name  of  MASTODON  (from  two  Greek  words, 
signifying  mammillary  teeth,)  has  been  given  to 
the  animal  to  whom  they  belonged.  These  teeth 
have  no  relation  to  those  of  the  carnivora ;  for 
although  they  have  an  external  investment  of 
enamel  like  those  of  the  tiger,  yet  they  are  desti- 
tute of  the  longitudinal,  serrated,  cutting  edge ; 
and  in  those  which  are  worn,  the  protuberances 
become  truncated  into  a  lozenge  form.  The  struc- 
ture is  similar  to  that  of  the  hog  and  the  hippopo- 
tamus, and  is  fitted  for  the  bruising  and  mastication 
of  crude  vegetables,  roots,  and  aquatic  plants. 
The  bones  and  teeth  of  the  mastodon  have  been 
found  throughout  the  plains  of  North  America, 
from  north  of  Lake  Erie  to  as  far  south  as  Charles- 
ton, in  South  Carolina;  they  have  been  also  dis- 
covered on  the  Continent,  and  in  the  Crag  of 
Norfolk,  in  England.  Here  are  examples  from 
the  banks  of  the  Ohio,  of  the  Hudson,  and  from 
L  2 


148  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

Big-bone  Lick,  presented  to  me  by  Professor  Silli- 
man :  this  is  an  example  of  a  young  perfect  tooth  ; 
and  this  of  a  very  old  animal,  for  the  grinding  surface 
is  almost  worn  flat  by  use.  These  remains  are  found 
at  moderate  depths,  with  no  marks  of  detrition ; 
it  is  therefore  evident  that  the  animals  must  have 
lived  and  died  in  the  country  where  their  relics  are 
entombed.  The  skeletons  of  the  great  mastodon 
found  in  the  bogs  of  Louisiana  are  in  a  vertical 
position,  as  if  they  had  sunk  in  the  mire ;  and  one 
discovered  in  New  Jersey,  forty  miles  to  the  south 
of  New  York,  was  bedded  in  black  earth,  in  the 
same  position,  the  head  being  on  a  level  with  the 
surface  of  the  soil.  There  is  an  entire  skeleton 
of  the  mastodon  in  the  museum  of  Mr.  Peale,  in 
Philadelphia,  which  is  fifteen  feet  long  and  eleven 
feet  high ;  and  by  this  specimen  it  has  been  ascer- 
tained that  the  great  mastodon,  or  animal  of  the 
Ohio,  as  it  has  been  called,  was  not  unlike  the 
elephant,  but  somewhat  longer  and  thicker.  It 
had  a  trunk  or  proboscis,  tusks,  and  four  molar 
teeth  in  each  jaw,  and  no  incisors.  Frdm  the  nature 
of  its  food,  as  shown  by  the  structure  of  the  teeth, 
it  must  have  frequented  marshy  tracts,  but  it  was 
undoubtedly  a  terrestrial  animal.  In  the  midst  of 
a  collection  of  these  bones  imbedded  in  mud,  a 
mass  of  small  branches,  grass,  and  leaves,  in  a 
half  bruised  state,  was  discovered,  and  a  species 
of  reed,  common  in  Virginia ;  the  whole  appeared 
to  have  been  enveloped  in  a  sack,  probably  the 


§  21.  MASTODONS  OF  NORTH  AMERICA.  149 

stomach  of  the  animal.  In  another  instance,  traces 
of  the  trunk  or  proboscis  were  observed.  The 
tusks  are  composed  of  ivory,  and  vary  in  their 
curvature.  The  bones  of  this  colossal  quadruped 
are  found  remarkably  fresh  and  well  preserved ; 
they  are  generally  impregnated  with  iron,  and  have 
evidently  been  buried  in  the  earth  for  ages.  No 
living  instance  of  this  creature  is  on  record,  and  no 
doubt  can  exist  that  its  race  has  long  been  extinct. 
The  Indians  believe  that  men  of  similar  proportions 
were  coeval  with  the  mastodon,  and  that  the  Great 
Spirit  destroyed  both  with  his  thunder.*  There 
are  several  species,  some  of  which  have  been  found 
in  North  America  only,  and  others  in  Europe. 
That  eminent  philosopher  Baron  Humboldt  dis- 
covered a  tooth  of  the  mastodon  near  the  volcano 
of  Imbaburra,  at  an  elevation  of  1,200  fathoms. 
A  very  fine  skull,  with  teeth,  of  the  great  mastodon, 
from  Big-bone  Lick,  has  lately  been  placed  in  the 
British  Museum,  and  is  well  worthy  your  notice 
when  visiting  that  magnificent  collection.  This 
specimen,  which  was  purchased  for  150  guineas, 
consists  of  the  cranium  with  two  perfect  grinders, 
and  the  sockets  of  the  other  two.  The  length  of 
the  skull,  from  the  occiput  to  the  sockets  for  the 
tusks,  is  36  inches. 

21.  MASTODONS  FOUND  IN  THE  BURMESE  EM- 
PIRE.— I  now  request  your  attention  to  the  remains 

*  Cuvier.     See  an  admirable  English  Epitome  of  Cuvier's 
Fossil  Animals,  by  Edward  Pidgeon,  Esq.  1  vol.  Svo,  1833. 


150  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

of  a  species  of  mastodon  which,  from  the  structure 
of  the  teeth,  fills  up,  as  it  were,  the  interval  that 
separates  the  mastodon  from  the  elephant  ;  it 


TAB.  26.— FOSSIL  TEETH  OP  THE  ELEPHANT  AND  MASTODON. 
(One-sixth  the  diameter  of  the  originals.') 

Fig.  1.  Tooth  of  the  fossil  Elephant  from  Big-bone-lick.    Fig.  2.  Tooth  of 
the  Mastodon  elephantoides  from  near  Ava. 

has  been  named  by  Mr.  Clift,  the  Mastodon  ele~ 
phantoides*  (Tab.  26,  fig.  2).  The  teeth,  which, 
together  with  the  fossil  bones  and  wood  before  us, 
I  owe  to  the  liberality  of  Mr.  Craufurd,  present 
characters  very  peculiar ;  for  while  their  structure 
is  similar  to  that  of  the  great  mastodon,  the 
ridges  in  which  the  crown  of  the  teeth  is  dis- 
posed, resemble  those  of  the  elephant;  and  the 
worn  surface  of  the  teeth  would  bear  an  analogy 
with  that  of  the  grinders  of  the  African  elephant. 
These  teeth,  together  with  bones  and  teeth  of  the 

*  Geological  Transactions,  vol.  ii.  new  series. 


§  21.  MASTODONS  IN  THE  BURMESE  EMPIRE.  151 

hippopotamus,  rhinoceros,  horse,  tapir,  ox,  antelope, 
hog,  gavial,   fresh-water  turtle,  &c.   and  silicified 
wood,  are  part  of  an  extensive  collection  formed 
about  ten  years  since  by  Mr.  Craufurd,  on  his  mis- 
sion to  Ava.    In  descending  the  river  Irawaddi,  his 
steam-boat,  owing  to  the  shallowness  of  the  water, 
ran  aground,  between  Prome  and  Ava,  about  20° 
north  latitude,  near  some  petroleum  wells,  where 
the  bank  of  the  river  presents  a  cliff  80  feet  high  ; 
and  on  the  strand  were  observed  masses  of  petrified 
wood,  and  vast  quantities  of  bones.     The  adjacent 
country  is  formed  of  low,  sterile  sand-hills,  inter- 
sected by  ravines,  with  beds  of  gravel,  which  are 
here  and  there  cemented  into  a  conglomerate  by 
iron  and  carbonate  of  lime,  by  the  process  which 
was  explained  in  the  former  lecture  (p.  64?).     Scat- 
tered  over   the  surface,   in   some  instances  lying 
loose  in  the  sand,  and  in  others  half  buried,  were 
masses  of  silicified  wood,  and  fragments  of  bones, 
which  had  become  exposed,  from  the  removal  of 
the  sand  by  the  winds  and  rains.     The  bones,  as 
you  may  perceive  in    these  incrusted  specimens, 
were  more  or  less  invested  with  a  hard  crust,  which 
appears  to  be  a  mere  local  concretion,  from  the 
consolidation    of  loose   sand    by  ferruginous   and 
calcareous  infiltrations.      The  natives  who  assisted 
Mr.  Craufurd's  party  in  collecting  these  remains, 
believed  that  they  were  the  bones  of  giants  who 
had  warred  against  Vishnu,  by  whom  they  had  been 
destroyed.      On  these  interesting  discoveries,  Dr. 


152  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

Buckland*  calls  attention  to  the  remarkable  fact, 
that  in  the  twelve  chests  full  of  osseous  remains, 
not  a  fragment  belongs  to  the  elephant,  tiger,  or 
hyena,  which  abound  in  India  ;  while  evidence  is 
afforded  that  the  extinct  mastodon  must  once  have 
swarmed  in  the  districts  bordering  on  the  Irawaddi. 
22.  THE  SIVATHERIUM.-)- — The  flanks  of  a  range 
of  hills  belonging  to  the  Sub-Himalaja  mountains, 
between  the  river  Sutlej  and  the  Ganges,  are 
covered  by  beds  of  concretionary  sandstone,  con- 
glomerate, and  loam,  bearing  a  close  analogy  to 
those  of  Ava.  These  hills,  which  are  called  the 
Sivalik,  (from  Siva,  an  Indian  deity,)  rise  to  an 
altitude  of  from  one  to  three  thousand  feet  above 
the  level  of  the  sea.  In  these  deposits  occur  im- 
mense quantities  of  fossil  teeth  and  bones  of  the 
elephant,  mastodon,  hippopotamus,  rhinoceros,  elk, 
ox,  horse,  deer ;  and  of  several  carnivorous  animals, 
crocodiles,  gavials,  and  fresh-water  turtles ;  with 
fluviatile  shells,  and  remains  of  fishes  ;  an  extinct 
species  of  monkey r,  and  of  the  camel  have  also  been 
found.  These  interesting  discoveries  were  made  by 
Captain  Proby  Cautley,  of  the  Bengal  artillery,  and 
Dr.  Falconer,  who,  with  an  energy  and  perseverance 
beyond  all  praise,  have  followed  out  their  researches, 
and  transmitted  magnificent  collections  of  these  re- 
mains to  England.  The  valuable  specimens  in  my 

*  See  a  Memoir  on  the  Bones  from  Ava,  by  Dr.  Buckland. 
Geol.  Trans,  vol.  ii.     New  Series, 
f  From  Siva,  an  Indian  deity,  and  therion,  wild  animal. 


§23.  THE  S1VATHERIUM.  153 

museum  were,  with  great  liberality,  sent  to  me  by 
Captain  Cautley;  among  them  you  may  observe 
bones  and  teeth  of  the  same  species  of  mastodon  as 
that  which  has  been  found  at  Ava ;  with  bones  of 
the  horse,  rhinoceros,  hippopotamus,  gavial,  and  a 
fine  sk'ull  of  the  fossil  elephant,  with  four  teeth 
perfect  and  in  place.  But  the  labours  of  these 
naturalists  have  been  yet  more  richly  rewarded  by 
the  discovery  of  the  skull,  and  other  parts  of  the 
skeleton,  of  a  creature  hitherto  unknown ;  one  that 
forms,  as  it  were,  a  link  between  the  ruminants  and 
the  large  pachydermata.  From  the  skull,  which  is 
remarkably  well  preserved,  it  is  ascertained  that 
the  animal  had  four  horns,  and  was  furnished  with 
a  proboscis  ;  that  it  was  larger  than  a  rhinoceros, 
and  combined  the  horns  of  a  ruminant,  with  the 
characters  of  the  pachydermata ;  the  discoverers 
have  named  it  Sivatkerium.  This  animal,  when 
living,  must  have  resembled  an  immense  antelope, 
or  gnu ;  with  a  short  and  thick  head,  an  elevated 
cranium,  crested  with  two  pairs  of  horns ;  the  front 
pair  were  small,  and  the  hinder  large,  and  set  quite 
behind,  as  in  the  aurochs.  With  the  face  and 
figure  of  the  rhinoceros,  it  must  have  had  small 
lateral  eyes,  great  lips,  and  a  nasal  proboscis ;  these 
inferences  have  been  deduced  from  certain  anato- 
mical characters  exhibited  by  the  fossil  bones,  but 
upon  which  I  cannot  enlarge. 

23.    THE  MEGATHERIUM.      (Mega,  great,  and 
therion,  wild  beast.) — The  Pampas,  those  immense 


154  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

plains  of  South  America,  on  the  south  bank  of  the 
river  Saladillo,  which  present  a  sea  of  waving  grass 
for  900  miles,  are  principally  composed  of  alluvial 
loam  and  sand,  containing  fresh-water  with  marine 
shells,  and  were  once,  like  Lewes  Levels,  a  gulf,  or 
arm  of  the  sea.    In  these  alluvial  deposits,  enormous 
bones  have  been  frequently  discovered.     Towards 
the  close  of  the  last  century,  an  almost  entire  ske- 
leton of  a  gigantic  animal  was  dug  up,  at  the  depth 
of  100  feet,  in  a  bed  of  clay,  on  the  banks  of  the  river 
Luxor,  about  four  leagues  W.S.W.  of  Buenos  Ayres. 
This  skeleton  was  sent,  in  1789,  to  the  museum  at 
Madrid,  where  it  now  remains.    It  is  described  and 
figured  by  Cuvier,  under  the  name  of  the  megathe- 
rium.    In  1832,  Sir  Woodbine  Parish,  with  con- 
siderable labour  and  expense,  collected  many  parts 
of  the  skeleton  of  a  similar  creature  from  the  Salado ; 
and  actually  diverted  for  a  time  the  river  from  its 
course,  that  he  might  disinter  these  precious  relics, 
which   he  has  since   deposited   in  the    Hunterian 
Museum  of  the  Royal  College  of  Surgeons.     But, 
before  I  enter  upon  a  description  of  these  fossils,  it 
will  be  requisite  to  notice  the  remains  of  an  animal 
of  analogous  structure,  which  has  been  discovered 
in  the  saltpetre  caves  of  Virginia  and  Kentucky, 
and  which,  from  the  size  of  the  unguical  or  claw- 
bones,  has  been  named  the  megalonyx. 

24.  THE  MEGALONYX.* — I  have  placed  upon  the 

*  Mega,  great ;  onyx,  claw.  See  a  "  Description  of  the 
Fossil  Bones  of  the  Megalonyx,"  in  Dr.  Harlan's  Medical  and 
Physical  Researches. 


§24.  THE  MEGALONYX.  155 

table,  models  of  all  the  bones  which  are  now  pre- 
served in  the  museum  of  Philadelphia,  for  which  I 
am  indebted  to  an  eminent  physician  and  geologist 
of  that  city,  Dr.  S.  G.  Morton,  the  author  of  the 
most  valuable  treatise  that  has  appeared  on  the 
fossils  of  the  United  States.*  The  late  American 
President,  Jefferson,  who  first  described  these  re- 
mains, inferred,  from  the  form  and  magnitude  of 
the  claw-bone,  that  the  original  was  a  carnivorous 
animal  of  colossal  proportions.  But  Cuvier,  by  his 
profound  knowledge  of  the  principles  of  anatomy, 
determined,  from  certain  characters  of  the  articu- 
lating surfaces,f  that  the  animal  was  related  to  the 
bradypus,  or  sloth.  I  will  endeavour  briefly  to 
explain  to  you  the  mode  by  which  this  induction 
was  obtained.  The  paws  or  feet,  both  of  the  canine 
and  feline  tribes,  are  armed  with  claws  ;  in  the  for- 
mer, the  nails  are  thick  and  coarse  as  in  the  clog, 
wolf,  &c.  and  fitted  to  bear  the  friction  and  pressure 
incident  to  a  long  chase  ;  while  in  the  cat  tribe,  on 
the  contrary,  they  are  curved  and  sharp,  which 
qualities  are  preserved  by  a  peculiar  mechanism. 
The  last  bone  which  supports  the  claw  is  placed 
laterally  to  the  penultimate  bone,  and  is  so  joined 
to  it  that  an  elastic  ligament  draws  it  back,  and 
raises  the  sharp  extremity  of  the  claw  upwards; 

*  Synopsis  of  the  Fossils  of  the  Cretaceous  Group  of  the 
United  States,  by  S.  G.  Morton,  M.D.  &c. 

f  That  surface  of  the  bone  which  forms  a  joint  with  another 
bone. 


156  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

and  the  nearer  extremity  of  the  farthest  bone 
presses  the  ground  in  the  ordinary  running  of  the 
animal,  while  the  claw  is  retracted  into  a  sheath  : 
but  when  the  creature  makes  a  spring  and  strikes, 
the  claws  are  uncased  by  the  action  of  the  flexors 
or  bending  tendons.  In  the  Bengal  tiger,  the  claws 
are  so  sharp  and  strong,  and  the  arms  so  powerful, 
that  they  have  been  known  to  fracture  the  skull  of 
a  man,  by  a  single  touch  in  the  act  of  leaping  over 
him.*  A  cat  affords  a  familiar  illustration  of  this 
peculiarity  of  structure;  when  pleased,  its  claws  are 
retracted,  and  when  angry  they  are  thrown  out. 
In  the  claw  of  the  megalonyx  there  is  no  such  lateral 
provision  for  its  retraction,  and  the  point  could  not 
have  been  raised  vertically,  as  in  the  cat,  so  as  to 
have  permitted  it  to  touch  the  ground  without 
injury.  The  articulating  surface  is  double,  that  is, 
there  is  a  ridge  or  spine  in  the  middle,  and  it  must, 
therefore,  have  moved  like  a  hinge. 

25.  THE  SLOTH. — There  is  among  recent  ani- 
mals an  order  called  tardigrada,  from  their  feeble 
power  of  progression — these  are  the  paresseux,  or 
sloths ;  which  have  long  toes,  and  large  nails,  of  a 
construction  similar  to  those  of  the  fossil.  Their 
nails  are  folded  up,  but  in  a  very  different  manner 
from  those  of  the  cat ;  they  only  enable  the  animal 
to  walk,  in  the  same  way  as  if  our  fingers  were 
folded  under  the  palms  of  the  hands.  This  is  a 

*  Sir  C.  Bell. 


§  25.  THE  SLOTH.  157 

specimen  of  the  bradypus  (slow-footed)  tridactylus^ 
(three-toed)  from  South  America,  and  which  is 
also  called  the  ai,  from  its  peculiar  cry.  The  arms 
are  double  the  length  of  the  legs,  and,  from  the 
construction  of  the  limbs,  the  animal,  when  it  walks, 
or  rather  crawls  on  the  ground,  is  obliged  to  drag 
itself  along  on  its  elbows.  But  these  creatures  are 
destined  to  inhabit  trees ;  their  proper  element  is 
on  the  branches,  and  they  can  pass  from  bough  to 
bough,  and  from  tree  to  tree,  with  a  rapidity  which 
soon  enables  them  to  lose  themselves  in  the  depths 
of  the  forests.  They  live  on  the  leaves  and  the 
young  shoots,  and  unless  disturbed,  never  quit  a 
tree  till  they  have  stripped  off  every  leaf.  To  avoid 
the  labour  of  a  descent,  they  drop  to  the  ground, 
previously  coiling  themselves  into  a  round  ball,  in 
which  state,  while  attached  to  the  branch,  they  may 
be  taken  alive.  Thus  the  habits  and  economy  of 
the  sloth  point  out  the  necessity  for  a  peculiarity 
of  structure  in  its  nails.  The  monkey  leaps  and 
swings  himself  from  tree  to  tree,  and  catches  at  will 
the  branches  or  the  trunk ;  but  the  sloths  do  not 
grasp  ;  their  claws  are  mere  hooks  to  hang  by,  and 
their  great  strength  is  in  their  arms.  They  never 
unfix  one  set  of  hooks  until  they  have  caught  a 
secure  hold  with  the  other,  thus  hanging  by  their 
arms  and  legs,  while  their  bodies  are  pendant ;  and 
they  sleep  in  the  same  position.  In  the  bones  of 
the  arm  of  the  megalonyx,  we  find  a  close  analogy 
with  those  of  the  sloths.  The  humerus,  or  arm- 


158  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

bone,  has  a  long  internal  condyle  for  the  origin  of 
very  large  muscles  to  move  the  enormous  claws ; 
and  there  is  a  foramen  or  opening  for  the  passage 
of  nerves  and  blood-vessels,  to  protect  them  from 
the  pressure  to  which  they  would  be  exposed  from 
the  powerful  muscular  action  ;  while  the  radius  is 
so  constructed  as  to  allow  of  a  rotatory  motion  of 
the  arm.  With  the  bones  of  this  animal  were 
found  masses  of  osseous  polygonal  scales,  like 
mosaic  work ;  and  it  is  supposed  that  the  original 
was  covered  with  an  armour  resembling  that  of  the 
armadillo. 

I  now  proceed  to  the  consideration  of  the  mega- 
therium. This  creature  was  about  seven  feet  high, 
and  nine  feet  long,  and  therefore  larger  than  the 
largest  rhinoceros;  but  this  comparison  by  no  means 
conveys  a  proper  idea  of  its  bulk,  since  its  propor- 
tions are  perfectly  colossal,  the  thigh-bone  being 
three  times  as  large  as  that  of  the  elephant,  and  the 
pelvis  or  haunch-bone,  twice  the  breadth.  It  pos- 
sessed no  incisor  teeth,  and  the  molars  or  grinders 
are  seven  inches  long,  of  a  prismatic  form,  and,  like 
those  of  the  elephant,  composed  of  ivory,  enamel,  and 
crusta  petrosa,  or  cement.  They  are  so  formed,  that 
the  crown  of  the  teeth  always  presents  two  cutting, 
wedge-shaped,  salient  angles.  As  in  an  adze  a  plate 
of  steel  is  placed  between  two  of  iron  so  as  to  pro- 
ject in  a  line,  in  like  manner  these  teeth  have  in  the 
centre,  a  cylinder  of  ivory,  which  is  protected  by  a 
plate  of  enamel,  and  has  an  external  coating  of 


§  25.  THE  MEGATHERIUM.  159 

crusta  petrosa  ;  these  teeth  are,  therefore,  admirably 
adapted  for  cutting  and  bruising  vegetable  matter. 
The  entire  fore-foot  is  about  a  yard  in  length,  and 
the  claws  are  set  obliquely  to  the  ground,  like  those 
of  the  mole ;  a  position  which  would  render  them 
digging  instruments  of  great  power.  The  pelvis 
measures  five  feet  in  width,  and  the  sacral  aperture 
of  the  spinal  marrow  is  one  foot  in  circumference ! 
This  enormous  size  was  suitable  to  the  habits  of  an 
animal  requiring  to  maintain  an  upright  posture 
for  a  considerable  time,  and  to  employ  its  fore-feet 
in  digging.  As  Dr.  Buckland  has  fully  elucidated 
the  structure  and  habits  of  this  enormous  being  of 
the  ancient  world,  and  his  work  is,  or  ought  to  be, 
in  every  library,  I  will  not  dwell  on  other  impor- 
tant peculiarities  in  its  osteology,  but  content  myself 
with  stating,  that  the  megalonyx  and  megatherium, 
were  intermediate  between  the  sloths,  armadillos, 
and  ant-eaters.  The  megatherium,  with  the  head 
and  shoulders  of  the  sloth,  combined  in  its  legs  and 
feet  an  admixture  of  the  characters  of  the  armadillo 
and  ant-eater.  Both  the  megalonyx  and  mega- 
therium were  herbivorous,  but  they  were  not 
capable  of  climbing,  even  had  there  been  trees 
that  could  have  supported  their  enormous  weight : 
their  food,  like  that  of  the  armadillos,  must  have 
consisted  of  roots  and  stems  of  succulent  vege- 
tables, which  the  peculiar  structure  of  their  feet 
enabled  them  to  dig  up  with  facility.  Like  their 
recent  types,  they  are  limited  in  their  geographical 


160  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

distribution  to  nearly  trie  same  regions  of  the  new 
world.* 

The  skeleton  of  another  colossal  quadruped  has 
very  recently  been  discovered  near  Buenos  Ayres, 
and  will  shortly  be  placed  in  the  Hunterian  Mu- 
seum, through  the  liberality  of  Sir  Woodbine 
Parish,  The  original  was  of  the  size  of  an  ox,  and 
covered,  like  the  armadillo,  by  an  armour,  formed 
of  polygonal  scales.  From  the  fluted  structure  of 
the  teeth,  this  animal  has  been  named  glyptodon, 
by  Professor  Owen. 

26.  FOSSIL  HIPPOPOTAMUS,  RHINOCEROS,  HORSE, 

&c. — With  the  fossil  remains  of  the  mammoth,  ele- 
phant, and  other  large  mammalia,  the  teeth  and 
bones  of  several  species  of  hippopotamus,  horse, 
elk,  ox,  and  auroch,  are  very  commonly  associated. 
In  the  Vale  of  Arno,  in  Italy,  immense  quantities  of 
the  teeth  and  bones  of  hippopotami  are  found.  On 
the  table  before  us  are  specimens  from  that  locality ; 
as  well  as  molars  and  incisors  of  a  young  animal 
from  Huntingdonshire,  presented  by  Mr.  Saull ;  and 
tusks,  teeth,  and  bones,  dug  up  in  alluvial  marl,  at 
Southbourn,  in  Sussex.  Bones  of  this  animal  also 
occur  in  alluvial  deposits  near  Rome ;  and  here  are 
examples,  collected  by  the  Marquis  of  Northampton. 
Among  the  objects  sent  me  by  Captain  Cautley, 
from  India,  are  several  fine  portions  of  jaws,  with 
teeth,  belonging  to  a  hippopotamus  (H.  Sivaliensis.) 
Several  extinct  species  of  hippopotamus  have  been 
*  See  Dr.  Buckland's  Bridgewater  Essay. 


§26.  FOSSIL  HIPPOPOTAMUS.  161 

determined  by  Baron  Cuvier,  one  of  which  was  not 
more  than  half  the  size  of  the  common  species. 
The  bones  and  teeth  of  the  rhinoceros  are  con- 
stantly associated  with  those  of  the  fossil  elephant ; 
and  in  this  country  they  occur  in  superficial  gravel 
and  loam  :  these  examples  of  teeth  were  discovered 
in  a  bed  of  gravel,  on  Petteridge  common,  in  Surrey. 
But  the  most  extraordinary  and  interesting  fact, 
relating  to  the  fossil  rhinoceros,  is  the  discovery  of 
the  entire  carcass,  with  the  skin,  in  frozen  sand,  on 
the  banks  of  the  Wilaji,  in  Siberia.  The  head  was 
extremely  large,  and  sustained  two  very  long  horns  ; 
it  had  no  incisors ;  the  body  was  covered  with 
brown  hair,  particularly  on  the  limbs ;  and  the 
general  form  of  the  animal  was  lower  and  more 
compact  than  the  living  species. 

The  teeth  and  bones  of  one  or  more  species  of 
horse,  occur  very  constantly  with  those  of  the  large 
extinct  pachydermata  ;  in  these  examples  of  the  con- 
glomerated shingle  from  Brighton  cliffs,  the  coffin, 
pastern,  and  cannon  bones,  as  they  are  termed, 
are  imbedded ;  in  some  instances  the  cavities  of  the 
long  bones  are  filled  with  crystallized  carbonate  of 
lime. 

In  addition  to  the  animals  we  have  already 
noticed,  the  deposits  now  under  examination  con- 
tain many  lost  species  of  ruminants,  and  of  other 
orders  of  mammalia.  The  fossil  remains  of  an 
animal  resembling  the  musk-ox  were  found  with 
elephants'  bones  in  Siberia;  an  extinct  species  of 
M 


162  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

fallow-deer  in  Scania  ;  of  roe-buck  and  reindeer  in 
France  ;  and  of  gigantic  oxen,  aurochs,*  deer,  &c.  in 
our  own  country.  It  is  worthy  of  remark,  that  the 
fossil  pachydermata,  such  as  the  elephant,  rhino- 
ceros, &c.  belong  to  genera  which  inhabit  torrid 
climes,  while  the  ruminants  are  of  those  which  at 
the  present  time  are  natives  of  northern  latitudes. 


TAB.  27.— THE  DINOTHERIUM. 

27.  THE  DINOTHERIUM. f — I  shall  conclude  my 
remarks  on  the  large  mammalia  with  the  description 
of  a  gigantic  creature  of  a  very  peculiar  character, 
whose  bones  occur  with  those  of  the  mastodon, 
elephant,  and  other  animals  which  we  have  already 

*  The  auroch  is  a  species  of  wild  bull  or  buffalo,  distinct 
from  the  common  ox.  The  horns  of  the  fossil  ox  are  some- 
times of  enormous  size  :  Mr.  Parkinson  had  a  pair  in  which 
the  length  of  each  horn  was  2  feet  7  inches. 

f  Dinos,  terrible  ;  therion,  a  wild  beast. 


{  j-7  THE  DINOTHERIUM.  163 

examined,  as  well  as  with  the  remains  found  in 
more  ancient  deposits.  In  various  parts  of  the 
south  of  France  large  molar  teeth,  resembling  in 
their  form  and  structure  the  teeth  of  tapirs,  have 
occasionally  been  found ;  they  are  described  by 
Cuvier  under  the  name  of  the  "  Gigantic  Tapir." 
Models  of  the  principal  specimens  deposited  in  the 
Museum  at  Paris,  have  been  presented  to  me  by 
Baron  Cuvier,  together  with  others  which  I  shall 
place  before  you  on  a  future  occasion.  Subsequent 
discoveries  in  Bavaria,  Austria,  and  particularly  at 
Eppelsheirn,  about  twelve  leagues  south  of  Mayence, 
have  made  us  acquainted  with  the  form  and  struc- 
ture of  the  original,  which  appears  to  have  been 
one  of  the  largest  of  lacustrine  animals,  the  skeletons 
showing  that  some  individuals  were  eighteen  feet  in 
length  I  The  scapula,  or  shoulder-blade,  was  like 
that  of  the  mole,  and  the  fore  leg  must  therefore 
have  been  adapted  for  digging  up  the  earth.  The 
most  extraordinary  deviation  from  ordinary  types 
consists,  however,  in  the  curved  tusks,  which  are 
fixed  in  the  lower  jaw  in  a  downward  direction,  as 
those  of  the  walrus  are  in  the  upper ;  the  lower 
jaw  is  four  feet  in  length.  From  the  structure  of 
the  anterior  portion  of  the  cranium,  and  the  dis- 
position of  the  nasal  fossae,  it  is  certain  that  the 
creature  had  a  proboscis ;  besides,  it  possesses  no 
incisor  teeth  with  which  to  seize  its  food,  and  the 
jaws  do  not  even  close  together  in  front.  The 
tusks  were  probably  weapons  of  defence,  like 
M2 


164  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

those  of  the 'elephant.  This  drawing,  (Tab.  27,) 
from  a  restoration  by  M.  Kaup,  an  eminent  German 
naturalist,  represents  the  supposed  form  of  the  ori- 
ginal creature.  It  would  appear  that  the  dino- 
therium  was  nearly  related  to  the  hippopotamus, 
forming  a  link  between  the  cetacea  and  pachyder- 
mata,  or  large  terrestrial  mammalia ;  and  that  it 
was  an  herbivorous  aquatic  animal,  inhabiting  lakes 
and  marshes. 

28.      FOSSIL      CARNIVORA     IN     CAVERNS. We 

have  passed  in  review  the  extinct  population  of  a 
remote  period  of  our  globe, — those  enormous  pachy- 
dermata,  the  mastodons  and  mammoths,  that  lie 
buried  in  the  alluvial  and  superficial  strata.  We 
now  arrive  at  the  consideration  of  phenomena  not 
less  interesting — the  occurrence  of  immense  num- 
bers of  skeletons  of  carnivorous  animals  in  fissures 
and  caverns.  In  the  former  discourse  I  alluded  to 
the  cavities  which  abound  in  certain  rocks  of  lime- 
stone, and  described  the  process  by  which  their 
roofs,  floors,  and  walls  were  coated  with  sparry 
incrustations,  and  ornamented  with  stalactites  and 
stalagmites  (p.  62).  Some  of  these  caverns  appear 
to  have  been  occasioned  by  the  destruction  of  the 
softer  portions  of  the  rock  by  subterranean  streams  ; 
others  are  so  extensive,  and  present  such  decided 
marks  of  angular  fracture,  as  to  leave  no  doubt  that 
they  have  been  produced  by  the  shocks  of  earth- 
quakes. The  occasional  occurrence  of  the  bones 
of  animals  in  such  cavities  might  reasonably  be 


§29. 


FOSSIL  CARNIVORA  IN  CAVERNS. 


165 


expected.  Those  that  admitted  of  easy  access  from 
without,  might  be  frequented  by  species  whose 
habits  lead  them  to  retire  into  dark  and  secret 
recesses  ;  while  others,  as  kids,  deer,  &c.  might  fall 
into  open  fissures,  and  their  bones  thus  become 
enveloped  and  preserved  in  calcareous  incrusta- 
tions. But  the  immense  quantities  of  only  one 
or  two  species  of  carnivora  that  are  found  in  some 
caverns,  show  that  these  have  been  for  a  long  period 
the  dens  of  extinct  species  of  bears,  wolves,  tigers, 
hyenas,  and  other  carnivorous  tribes.  - 


TAB.  28.— VEKTICAL  SECTION  OP  THE  CAVE  OP  GAYLENREUTH. 


29.  CAVE  OF  GAYLENREUTH. — For  many  cen- 
turies, certain  caverns  in  Germany  have  been  cele- 
brated for  their  osseous  treasures,  particularly  those 


166  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

in  Franconia  :  the  most  remarkable  is  that  of 
Gaylenreuth,  which  lies  to  the  north-west  of  the 
village,  on  the  left  bank  of  the  river  Wiesent.  The 
entrance,  which  is  about  seven  feet  high,  is  in  the 
face  of  a  perpendicular  rock,  and  leads  to  a  series 
of  chambers  from  fifteen  to  twenty  feet  high,  and 
several  hundred  feet  in  extent,  terminated  by  a 
deep  chasm,  which,  however,  has  not  escaped  the 
ravages  of  visitors.  This  cavern  is  perfectly  dark, 
and  the  icicles,  or  pillars  of  stalactite,  reflected  by 
the  torches  which  it  is  necessary  to  use,  present  a 
highly  picturesque  and  striking  effect.  The  floor 
is  literally  paved  with  bones  and  fossil  teeth;  and 
the  pillars  and  corbels  of  stalactite  also  contain 
osseous  remains.  Loose  animal  earth  abounding  in 
bones,  forms  in  some  parts  a  layer  ten  feet  in  thick- 
ness. A  graphic  description  of  this  cave  was 
published  by  M.  Esper,  more  than  sixty  years  ago ; 
at  that  period,  some  of  the  innermost  recesses 
contained  waggon  loads  of  bones  and  teeth ;  some 
imbedded  in  the  rock,  and  others  in  the  loose  earth. 
The  bones  in  general  are  scattered  and  broken,  but 
not  rolled ;  they  are  lighter  and  less  solid  than 
recent  bones,  and  are  often  incrusted  with  stalac- 
tite. Through  the  kindness  of  Lord  Cole,  and  Sir 
Philip  de  M.  Grey  Egerton,  I  am  able  to  illustrate 
these  remarks  by  an  extensive  suite  of  osseous 
remains,  exhumed  from  the  deepest  recess  in  the 
cavern,  and  collected  a  short  time  since  by  these 
distinguished  geologists.  But  the  most  interesting 


§29.  CAVE  OF  GAYLENREUTH.  107 

specimen  in  my  possession  is  a  remarkably  perfect 
skull  of  a  bear,  which  belonged  to  my  late  friend 
Mr.  Parkinson,  the  author  of  that  delightful  work, 
"  The  Organic  Remains  of  a  Former  World."  A 
comparison  of  this  relic  with  the  skull  of  the  polar 
bear,  shows  that  it  must  have  belonged  to  a  species 
of  ursus.*  Cuvier,  who  enjoyed  the  opportunity 
of  examining  a  very  large  collection  of  bones 
from  Gaylenreuth,  was  enabled  to  determine  that 
at  least  three-fourths  of  the  osseous  contents  of  the 
caverns  belonged  to  some  species  of  bear ;  and  the 
remaining  portion  to  hyenas,  tigers,  wolves,  foxes, 
gluttons,  weasels,  and  other  small  carnivora.  By 
the  bones  which  were  referable  to  the  bear,  he 
established  three  extinct  species  of  that  genus ; 
the  largest  of  these  has-a  more  prominent  forehead 
than  any  living  species,  and  is  called  the  Ursus 
spelceus,  or  bear  of  the  caverns,  and  it  is  to  this 
species  the  skull  I  have  just  mentioned  belongs ;  the 
other  has  a  flatter  forehead,  and  has  been  named 
Ursus  arctoidaus.  The  hyena  was  allied  to  the 
spotted  hyena  of  the  Cape,  but  differed  in  the 
form  of  its  teeth  and  head.  Bones  of  the  elephant 
and  rhinoceros  are  also  said  to  have  been  dis- 
covered, together  with  those  of  existing  animals, 

*  Their  Royal  Highnesses  the  Princes  George  of  Cumberland 
and  Cambridge,  when  inspecting  my  collection  a  few  years 
since,  at  Lewes,  pointed  out  this  skull  to  me  as  resembling 
some  fossils  that  had  been  exhumed  from  a  fissure  in  limestone, 
in  the  kingdom  of  Hanover. 


168  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

and  fragments  of  sepulchral  urns  of  high  anti- 
quity. 

30.  FORSTER'S  HOHLE. — Another  cavern  in  this 
part  of  Germany  is  mentioned  by  Dr.  Buckland,  as 
one  of  the  most  remarkable  for  the  beauty  of  its 
incrustations.  It  is  called  Forster's  Hohle,  and  varies 
in  height  from  ten  to  thirty  feet ;  its  greatest  width 
is  about  ten  yards.  In  the  side  vaults  or  recesses, 
which  descend,  at  an  angle  of  about  forty-five 
degrees,  into  the  main  chamber,  the  stalagmite  has 
formed  the  appearance  of  cascades  of  pure  alabaster, 
the  waves  of  which  seem  to  be  rushing  out  at  the 
bottom,  to  pour  themselves  into  the  stagnant  lake 
of  the  same  substance  which  covers  the  floor.  The 
rocky  roof  has  been  corroded  into  deep  cavities, 
which  are  separated  by  partitions  of  every  con- 
ceivable form  and  tenuity,  giving  it  the  appearance 
of  the  richly  fretted  gothic  roof  of  a  chapel,  with 
pendent  corbels.  Beautiful  stalactites  depending 
from  these  projections,  reach  almost  to  the  floor, 
and  contribute  by  their  delicacy  and  transparency 
to  throw  additional  richness  over  the  scene. 

It  is  certainly,  as  M.  Cuvier  remarks,  a  most 
extraordinary  fact,  that  caves,  spread  over  an  extent 
of  two  hundred  leagues,  should  have  the  same 
osseous  contents.  The  relative  proportions  of  the 
different  species  are  computed  to  be  as  follow : — 
three-fourths  belong  to  bears — two-thirds  of  the 
remainder  to  hyenas — and  a  small  number  to  the 
tiger  or  lion,  and  to  the  wolf  or  dog ;  rolled  pebbles 


§  31.          BONE  CAVERNS  IN  ENGLAND.          169 

of  a  greyish  blue  marble  are  the  only  extraneous 
materials  found  with  the  bones.  Let  me  here  call 
your  attention  to  the  singular  association  of  species 
which  some  of  these  caves  present;  their  recent 
types  being  widely  separated.  Thus  in  one  cavern, 
animals  allied  to  the  spotted  hyena  of  the  Cape  of 
Good  Hope,  are  collocated  with  the  remains  of 
others  related  to  the  glutton,  which  inhabits  Lap- 
land; and  in  another,  bones  of  the  rhinoceros  are 
associated  with  those  of  the  reindeer.  Numerous 
caves  containing  osseous  remains  are  scattered  over 
the  continents  of  Europe  and  America ;  and  even 
in  Australia,  fossil  bones  belonging  to  animals  of 
different  genera,  but  in  a  similar  state  of  preserva- 
tion, are  found  in  caverns. 

31.  BONE  CAVERNS  IN  ENGLAND — KIRKDALE 
CAVE. — In  England  caverns  containing  bones  of 
bears,  and  other  carnivora,  in  every  respect  analo- 
gous to  those  of  Germany  which  we  have  just 
described,  have  been  discovered  and  explored. 
Dr,  Buckland,  in  his  valuable  work,  the  Reliquice 
Diluviance,  has  noticed  several  of  the  most  impor- 
tant assemblages  of  this  kind.  The  cave  of  Kirk- 
dale,  now  so  well  known  in  consequence  of  the 
highly  interesting  disquisition  on  its  contents  by  my 
distinguished  friend,  is  one  of  the  most  celebrated. 
In  the  summer  of  1821,  a  cave  was  discovered  near 
Kirkdale,  about  twenty-five  miles  NN.E.  of  York, 
in  a  bank  about  sixty  feet  above  the  level  of  a  small 
valley,  and  near  a  public  road.  Some  workmen 


170  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

who  were  quarrying  stone,  cut  across  the  narrow 
mouth  of  a  chasm,  which  had  been  choked  up  with 
rubbish,  and  overgrown  with  grass  and  bushes; 
and  which  from  this  cause,  as  well  as  from  its 
inaccessible  situation,  had  hitherto  escaped  obser- 
vation, the  entrance  being  so  small  that  it  was  only 
possible  for  a  person  to  enter  in  a  bent  position. 


P 

4  feet. 
TAB.  29.— SECTION  OP  THE  ENTRANCE  OP  THE  CAVE  OP  KIRKDALE.* 

A.  Mud  covering  the  floor  of  the  cave  to  the  depth  of  one  foot,  and  con- 

cealing the  bones. 

B.  Stalagmite  incrusting  some  of  the  bones,  and  formed  before  the  mud 

was  introduced. 

C.  C.  Stalagmite  formed  over  the  mud. 

D.  Insulated  stalagmite  on  the  surface  of  the  mud. 

E.  E.  Stalactites  dependent  from  the  roof. 

The  passage  is  exceedingly  irregular  in  its  dimen- 
sions, varying  from  two  to  seven  feet  in  breadth, 
and  from  two  to  fourteen  feet  in  height;  its  greatest 
length  is  245  feet.  It  divides  into  several  smaller 

*  From  Dr.  Buckland's  Reliq.  Diluv. 


§31.  KIRKDALE  CAVE.  171 

passages,  which  have  not  yet  been  explored,  as 
they  are  nearly  closed  by  stalactital  concretions ; 
these  cavities  occur  where  the  roof  is  intersected 
by  fissures,  which  are  continued  for  a  few  feet,  but 
are  gradually  lost  in  the  superincumbent  limestone, 
and  are  thickly  lined  with  stalactites.  The  true 
floor  was  only  seen  near  the  entrance,  for  in  the 
interior  the  whole  was  covered  with  a  bed  of  har- 
dened mud  or  clay,  about  a  foot  in  average  thickness. 
The  surface  was  perfectly  smooth  and  level  when 
the  cave  was  first  opened,  except  where  stalagmites 
had  formed  upon  it  by  infiltration  from  the  roof. 
Where  stalactitic  matter  incrusted  the  sides,  it  also 
extended  over  the  bottom  like  a  thin  coat  of  ice ; 
and  therefore  must  have  been  formed  since  the  mud 
was  introduced.  This  mud  or  clay  was  filled  with 
fragments  of  bones  belonging  to  a  great  variety  of 
animals  ;  and  some  of  the  bones  exhibited  marks  of 
having  been  gnawed.  From  many  corroborative 
circumstances  these  appearances  are,  with  much 
probability,  supposed  to  have  been  occasioned  by 
hyenas.  The  bones  thus  preyed  upon  belong  to 
the  tiger,  bear,  wolf,  fox,  weasel,  elephant,  rhino- 
ceros, hippopotamus,  horse,  ox,  and  deer.  Bones 
of  a  species  of  hare  or  rabbit,  water-rat,  and  mouse, 
with  fragments  of  the  skeletons  of  ravens,  pigeons, 
larks,  and  ducks,  were  also  imbedded  with  these 
remains. 

From    these   facts  it  is  inferred   that   the   cave 
was  inhabited  by  hyenas  for  a  considerable  period, 


172  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

that  many  of  the  remains  found  there  were  of 
species  which  had  been  carried  in,  and  devoured 
by  those  animals,  and  that  in  some  instances  the 


TAB.  30.— THE  LEFT  SIDE  op  THE  LOWER  JAW  op  A  HYENA,  FROM 

KlRKDALE    CAVE. 


hyenas  preyed  upon  each  other.  Portions  of  ele- 
phants' bones  seem  to  show  that  occasionally  the 
large  mammalia  also  served  as  food  ;  but  it  is 
probable  that  many  of  the  smaller  animals  were 
drifted  in  by  currents,  or  fell  into  the  chasm, 
through  fissures  now  closed  up  by  stalactitical  in- 
crustations. 

KENT'S  CAVE,  near  Torquay,  which  is  nearly 
600  feet  in  length,  has  yielded  immense  quantities 
of  bones  of  carnivora  ;  and  in  the  Isle  of  Portland, 
at  Plymouth,  and  in  the  Mendip  Hills,  similar 
accumulations  have  been  found.  In  the  south-east 
of  England  but  one  instance  is  known ;  a  fissure  in 
the  sand-rock  at  Boughton  Quarries,  near  Maid- 
stone,  contained  the  jaw  and  bones  of  a  hyena, 


§  32.         DISEASED  BONES  OF  CARNIVORA  IN  CAVES.        173 

which  are  now  in  the  museum  at  Oxford.  This 
fact  proves  the  existence  of  the  same  condition  of 
animated  nature  in  this  part  of  our  island,  as  in  the 
districts  previously  mentioned.  Very  recently  a 
cave  has  been  discovered  near  Plymouth,  in  which 
bones  of  hyenas  were  found  in  abundance,  associated 
with  those  of  the  elephant,  rhinoceros,  horse,  &c. 

From  what  has  been  stated,  we  learn  that  our 
wastes  and  forests  were  once  inhabited  by  extinct 
carnivora,  belonging  to  genera  whose  recent  species 
are  almost  entirely  restricted  to  southern  climates ; 
— that  these  lived  and  died  for  successive  gene- 
rations, and  were  the  prey  or  the  destroyers  of  each 
other; — that  the  hyenas,  according  to  their  peculiar 
habits,  dragged  into  their  dens  the  creatures  which 
they  killed  or  found  dead,  and  devoured  them  at 
their  leisure  ; — that  subsequently  the  races  were 
annihilated,  and  were  succeeded  by  animals  of  a 
character  altogether  different. 

32.  DISEASED  BONES  OF  CARNIVORA  FOUND  IN 
CAVES. — Among  the  bones  found  in  the  caves  of 
Germany  are  many  in  a  condition  which  must  have 
resulted  from  accident  or  disease.  In  some  there 
has  been  a  formation  of  new  bony  matter  to  repair 
fractures;  in  others  there  is  anchylosis,  or  adhesion 
of  the  joints  from  inflammation  :  while  in  some  the 
effects  of  caries,  or  decay  of  the  bones,  the  result  of 
tedious  and  painful  diseases,  are  apparent.  Others 
have  a  light  and  spongy  character,  and  are  very 
fragile,  which  must  have  arisen  from  a  want  of 


174  THE  WONDERS  OF  GEOLOGY.  LECT.  II, 

energy  in  the  nutritive  system,  in  consequence  of 
a  scrofulous  affection.* 

33.  HUMAN  BONES,  AND  WORKS  OF  ART,  ix 
CAVERNS.— ^Bones  of  man,  and  fragments  of  ancient 
pottery,  have  been  found  in  caves,  both  in  France 
and  Germany ;  a  circumstance  perfectly  natural, 
since  we  are  well  aware  that  mankind,  in  a  rude 
state,  have  been  in  the  habit  of  living  in  caves,  and 
traces  of  their  having  inhabited  recesses,  which 
had  previously  been  the  retreat  of  wild  animals, 
were  therefore  to  be  expected.  But  as  bones  of 
extinct  animals  occurred  with  them,  it  was  rashly 
assumed  that  they  were  coeval  with  each  other ; 
more  accurate  observations  have,  however,  shown 
that  the  human  remains  were  introduced  at  a  sub- 
sequent period.  We  have  historical  proof  that  the 
early  inhabitants  of  Europe  often  resided,  or  sought 
shelter  in  caves.  Thus  Florus  records,  that  Caesar 
ordered  the  inhabitants  of  Aquitania  to  be  inclosed 
in  the  caverns  to  which  they  had  retired.  Many 
tribes  of  the  Celtic  race  occupied  these  subterranean 
retreats,  not  only  as  a  refuge  in  time  of  war,  but 
also  for  shelter  from  cold ;  as  magazines  for  their 
corn,  and  for  the  produce  of  the  chase ;  and  as 
places  of  concealment  for  the  animals  which  they 
had  domesticated.  The  bones  of  such  of  these 
people  as  perished,  or  were  buried  in  these  caverns, 

*  Professor  Walther,  on  the  antiquity  of  diseases  of  bones ; 
see  Professor  Jameson's  Cuvier's  Theory  of  the  Earth.  Edin. 
1827. 


§34.      OSSEOUS  BRECCIA,  OR  BONE  CONGLOMERATE.       175 

would  become  blended  with  the  mud,  gravel,  arid 
debris  of  the  animals  already  entombed  ;  and  a 
stalagmitical  paste  would  in  some  places  be  formed 
by  the  infiltration  of  water,  as  at  Bize,  and  would 
thus  cement  the  whole  into  solid  aggregates.  We 
should  therefore  expect  to  find  masses  of  stone, 
containing  bones  of  the  bear,  and  other  extinct 
species,  associated  with  human  bones,  fragments  of 
pottery,  terrestrial  shells,  and  bones  of  animals  of 
modern  times.  Such  are  the  contents  of  numerous 
caves,  and  the  above  explanation  points  out  the 
mode  in  which  such  accumulations  have  taken 
place.* 

34.  OSSEOUS  BRECCIA,  OR  BONE  CONGLOME- 
RATE.— The  facts  we  have  next  to  examine  are 
even  more  extraordinary  than  those  which  have 
already  been  described  ;  for  the  osseous  remains 
which  now  claim  our  attention  are  not  imbedded 
in  gravel  or  clay,  or  collected  together  in  caves,  but 
are  found  in  fissures  of  limestone,  extending  over 
an  area  of  many  hundred  leagues,  and  occurring  in 
rocks  and  islands,  very  remote  from  each  other. 
The  limestone  presents  but  little  variety,  the  sub- 
stance in  which  the  bones  are  enveloped  is  every- 
where the  same,  and  the  fossil  remains  belong, 
with  but  few  local  exceptions,  to  similar  species  of 
animals.  The  rocks  are  split  in  every  direction, 
and  the  fissures  filled  with  what  geologists  term 
an  osseous  or  bone-breccia ;  that  is,  bones,  and 
*  Memoir  by  M.  Desnoyer. 


176 


THE  WONDERS  OF  GEOLOGY. 


LECT.  II. 


fragments  of  bones,  held  together  by  a  calcareous 
cement  or  paste,  in  the  same  manner  as  the  con- 
glomerated shingle  of  Kemp-Town  ;  or,  to  exem- 
plify its  nature  by  a  still  more  familiar  illustration, 
the  mixture  of  mortar,  pebbles,  &c.  employed  in 
masonry,  and  called  concrete.  This  cement  is  of 
a  reddish  brown,  very  much  resembling  common 
brick ;  and  the  bones  are  beautifully  white,  having 
in  many  instances  their  cavities  lined  with  spar, 
as  in  these  specimens  from  Gibraltar.  In  some 
examples  the  bones  have  undergone  but  little 
change  ;  in  others,  the  cells  of  the  cancellated 
structure,  are  filled  with  calcareous  matter,  as  you 
may  observe  in  this  specimen  from  Cerigo,  (pre- 
sented to  me  by  Lady  Mantell,)  which  is  cut  and 
polished,  to  show  the  internal  structure  of  the  bones. 


TAB.  31.— TOOTH  OF  A  RUMINANT  IN  OSSEOUS  BRECCIA,  FROM 
GIBRALTAR, 

This  tooth  of  a  species  of  ruminant  (Tab.  31)  frc 


§  35.  THE  ROCK  OF  GIBRALTAR.  177 

Gibraltar,  resembles  in  its  general  appearance  the 
teeth  found  in  the  Coombe-rock  of  the  Brighton 
cliffs.  But  the  stone  to  which  it  is  attached  is 
more  compact,  and  partakes  of  the  character  of 
marble ;  it  is  of  a  dull  red  colour,  mottled  with 
white,  and  is  susceptible  of  a  good  polish.  This 
osseous  breccia  occurs  on  the  northern  shores  of 
the  Mediterranean ;  in  the  rock  of  Gibraltar ;  at 
Cette,  Nice,  and  Antibes ;  in  Dalmatia,  and  in  the 
isles  of  Cerigo,  Corsica,  &c. ;  and  in  Sicily,  Sardi- 
nia, and  many  parts  of  Germany.  Each  of  these 
localities  present  highly  interesting  examples  of  the 
subject  of  our  present  inquiry. 

35.  THE  ROCK  OF  GIBRALTAR. — The  rock  of 
Gibraltar,  so  well  known  from  its  historical  and 
political  importance,  affords  an  admirable  illustra- 
tion of  the  phenomena  under  review  ;  and,  for  the 
sake  of  brevity,  I  shall  chiefly  confine  my  observa- 
tions to  that  celebrated  spot.  Gibraltar  is  situated 
on  the  Spanish  side  of  the  Mediterranean,  being 
united  to  the  main  land  by  a  narrow  isthmus,  which 
is  about  three-fourths  of  a  mile  broad,  eight  or  ten 
feet  above  the  level  of  the  sea,  and  formed  of  con- 
solidated sand.  The  rock  stands  on  the  western 
extremity  of  the  area  in  which  the  osseous  breccia 
occurs,  and  its  greatest  altitude  is  about  1,350  feet. 
It  is  in  great  part  composed  of  a  compact,  bluish- 
grey  marble,  which,  like  most  extensive  limestone 
masses,  is  cavernous.  The  principal  cavern,  called 
St.  Michael's,  contains  stalagmites  and  stalactites, 


178  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

which  when  polished  are  of  great  beauty.  In  the 
fissures  intersecting  the  rock,  as  well  as  in  some  of 
the  caves,  a  calcareous  concretion,  of  a  reddish- 
brown  colour,  occurs,  which  in  some  parts  is  a  mere 
earthy  mass,  but  in  others  is  highly  indurated.  The 
bones  are  commonly  in  a  broken  state,  and  but 
seldom  water- worn ;  and  the  fragments  of  limestone, 
with  which  the  fissures  abound,  are  also  angular, 
and  have  evidently,  like  the  bones,  fallen  into  the 
crevices  at  different  periods,  and  been  gradually 
incrusted  and  conglomerated  by  calcareous  infil- 
trations. Snails  and  other  land  shells  often  occur 
impacted  in  the  solid  breccia ;  they  belong  to  the 
existing  species  of  the  country.  As  the  concretion 
is  still  in  progress  of  formation,  masses  may  be  found 
with  terrestrial  shells  unmixed  with  bones.  The 
cementing  material  is  very  similar  in  the  different 
localities  where  the  breccia  has  been  observed  ; 
namely,  at  Cette,  Nice,  Antibes ;  in  Dalmatia  and 
Sardinia.  The  animal  remains  of  the  breccia  are 
referable  to  several  species,  some  of  which  are 
recent  and  others  extinct,  of  deer,  antelope,  rabbit, 
rat,  mouse,  &c.  Bones  of  birds  and  of  lizards  have 
been  discovered  at  Cette ;  and  of  lemmings,*  and 
of  the  lagomys,"\  which  now  only  exists  in  Siberia : 
it  is  but  rarely  that  traces  of  carnivora  are  observed. 
No  one  can  fail  to  be  struck  with  surprise  at  the 

*  Lemming,  or  Lapland  marmot. 

f  Signifying  rat-hare.     A  genus  of  animals  which  forms  a 
link  between  the  hare  and  the  rat. 


§3«.  OSSEOUS  BRECCIA  OF  AUSTRALIA.  179 

occurrence  of  these  isolated,  yet  analogous  pheno- 
mena, which  surround  the  great  basin  of  the  Medi- 
terranean— rocks  of  a  uniform  character,  fissured  and 
broken,  their  rents  filled  up  with  similar  materials, 
and  with  the  remains  of  the  same  species  of  animals. 
The  occurrence  of  species,  either  extinct,  or  no 
longer  inhabiting  the  same  latitudes  (as  the  lago- 
mys),  refers  the  period  of  the  existence  of  these 
animals  to  the  epoch  of  the  mammoths  and  masto- 
dons ;  and  the  absence  of  marine  remains,  and  of 
the  usual  abrading  effects  of  water,  show  that  the 
breccia  was  formed  on  dry  land,  and  not  beneath 
the  sea. 

The  rational  explanation  of  these  facts  appears 
to  be  that  which  assumes  the  original  union  of  these 
-distant  rocks  and  islands  into  a  continent,  or  large 
island,  which,  like  Calabria,  was  subject  to  repeated 
visitations  of  earthquakes ;  and  that  the  animals 
which  inhabited  the  country  fell  into  the  fissures 
thus  produced,  and  were  preserved  by  the  calca- 
reous infiltrations  that  were  constantly  in  progress. 
Subsequent  convulsions  severed  the  country  into 
rocks  and  insular  masses,  of  which  catastrophe  the 
osseous  conglomerates  are  the  physical  and  only 
record. 

36.  OSSEOUS  BRECCIA  OF  AUSTRALIA. — Caves 
and  fissures,  filled  with  osseous  breccia,  in  the  same 
manner  with  those  I  have  described,  have  also  been 
discovered  in  New  Holland,  to  the  westward  of 
Sydney,  near  the  banks  of  the  Macquarrie  river ; 
N  2 


180  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

and  it  is  not  a  little  remarkable,  that  even  the  red 
ochreous  colour  of  the  European  conglomerates 
prevails  ;  the  bones,  however,  belong  to  animals 
wholly  distinct  from  any  hitherto  noticed  in  the 
preceding  examples.  Some  of  them  are  of  living, 
others  of  extinct  species,  but  all  of  them  are  refer- 
able to  marsupial  animals,  as  the  kangaroo^  wombat, 
dasyuruS)  &c.  A  portion  of  a  large  bone,  found 
in  a  cave,  is  said  to  resemble  the  leg-bone  of  the 
hippopotamus,  but  this  requires  confirmation  ;  it  is, 
however,  a  subject  worthy  of  attention,  since  the 
kangaroo  is  the  largest  animal  now  known  in  those 
regions.  The  fact  that  all  the  fossil  animals  of 
Australia  hitherto  discovered,  are  marsupial,  that 
is,  belong  to  the  mammalia  which  carry  their  young 
in  a  pouch — a  type  of  organization  which  is  the 
peculiar  feature  of  the  existing  races  of  the  coun- 
try— is  also  of  great  interest ;  for  it  proves  that  the 
present  zoological  character  of  those  regions  has 
prevailed  from  a  very  remote  period. 

37.  RETROSPECT. — I  must  now  bring  to  a  close 
this  examination  of  the  ancient  superficial  deposits 
— those  accumulations  of  alluvial  matter,  which 
taken  as  a  whole,  are  referable  to  a  far  more 
early  period  than  those  which  strictly  belong  to  the 
modern  or  human  epoch.  And  as  in  the  former 
discourse  I  found  it  necessary  to  dwell  on  the  dis- 
coveries of  astronomy,  to  elucidate  some  of  the 
physical  changes  of  our  planet ;  in  the  present  I 
have  summoned  comparative  anatomy  to  our  aid, 


§37.  RETROSPECT.  181 

and  have  endeavoured  to  point  out  the  mode  of 
induction  pursued  by  the  palaeontologist,  in  his 
inquiries  into  the  fossil  remains  of  animal  organiz- 
ation, by  which  he  is  enabled  to  call  forth  from 
their  rocky  sepulchres,  the  beings  of  past  ages,  and 
like  the  fabled  sorcerer,  give  form  and  animation  to 
the  inhabitants  of  the  tomb. 

From  the  facts  that  have  been  presented  to  us  in 
the  course  of  this  lecture,  we  arrive  at  the  following 
important  inferences : — 

First — that  the  extinction  of  certain  forms  of 
animal  existence  is  a  law,  which  is  not  only  in  ope- 
ration at  the  present  moment,  but  has  extended 
throughout  the  period  comprehended  in  our  present 
researches ;  and  we  have  traced  its  influence  from 
the  partial  extirpation  of  certain  existing  species,  to 
the  entire  annihilation  of  many  species  and  genera 
that  once  were  contemporary  with  man  ;  as  well  as 
to  those  which  are  known  to  have  lived,  and  become 
extinct,  prior  to  the  creation  of  our  race. 

Secondly — that  while  in  the  modern  marine  and 
fluviatile  accumulations,  the  remains  of  existing 
species  of  animals,  and  of  man  and  his  works,  are 
entombed,  in  the  ancient  deposits  of  water-worn 
materials,  those  of  larger  mammalia  alone  are  im- 
bedded. 

Thirdly — that  the  animal  remains  principally 
belong  to  extinct  pachydermata,  related  to  the 
elephant,  hippopotamus,  sloth,  horse,  deer,  and 
other  ruminants  ;  and  that  these  had  for  their 


182  THE  WONDERS  OF  GEOLOGY.  LECT.  II. 

contemporaries,  bears,  hyenas,  tigers,  and  other 
carnivora  of  species  now  extinct. 

Fourthly — that  there  was  therefore  a  period  im- 
mediately preceding  the  existence  of  man,  when 
the  earth  teemed  with  large  herbivorous  animals, 
which  roamed  through  the  primeval  forests  unmo- 
lested, save  by  beasts  of  prey.  Numerous  species 
and  entire  genera  have  been  swept  away  from  the 
face  of  the  earth, — some  by  sudden  revolutions, 
others  by  a  gradual  extinction, — while  many  have 
been  exterminated  by  man. 

Lastly — that  these  various  strata,  whether  formed 
in  the  beds  of  lakes  or  rivers,  in  estuaries,  or  in  the 
depths  of  the  ocean,  have  been  elevated  above  the 
level  of  the  sea,  and  now  constitute  fertile  coun- 
tries, supporting  the  busy  population  of  the  human 
race. 


I  have  thus  endeavoured  to  interpret  one  page  of 
the  ancient  physical  history  of  our  planet,  and  to 
explain  the  records  of  one  epoch  in  geological 
chronology.  We  have  entered  upon  the  confines  of 
the  past,  and  already  we  find  ourselves  surrounded 
by  an  innumerable  population  of  unknown  types  of 
being, — not  as  dim  and  shadowy  phantoms  of  the 
imagination, — but  in  all  the  reality  of  form  and 
structure,  and  bearing  the  impress  of  the  mighty 
changes  of  which  they  constitute  the  imperishable 
memorials.  We  have  again  witnessed  the  effects  of 
the  continual  mutations  of  the  land  and  water, — 


§37.  RETROSPECT.  183 

have  seen  that  our  present  plains  and  valleys  were 
submerged  beneath  the  ocean,  at  a  period  when 
large  mammalia,  apparently  unrestricted  by  existing 
limits  of  climate,  were  inhabitants  of  regions  which 
are  now  no  more — and  we  have  obtained  additional 
proof  that — 

New  worlds  are  still  emerging  from  the  deep, 
The  old  descending  in  their  turn  to  rise ! 

Even  in  this  early  stage  of  our  progress,  we  have 
conclusive  evidence  of  the  extinction  of  whole  tribes 
of  animals,  equally  admirable  in  their  adaptation  to 
the  conditions  in  which  they  were  placed,  as  the 
races  which  now  exist.  And  delightful  it  is  to 
the  geologist,  to  find  that  this  fact,  which  but  a  few 
years  since  was  received  with  hesitation  by  most, 
and  condemned  and  rejected  by  many,  is  now  ad- 
duced by  the  moralist  and  the  divine,  as  affording 
new  proofs  of  the  wisdom  and  overruling  providence 
of  the  Eternal.  Reflecting  on  these  phenomena, 
the  mind  recalls  the  impressive  exclamation  of  the 
poet — 

My  heart  is  awed  within  me,  when  I  think 
Of  the  great  miracle  which  still  goes  on 
In  silence  round  me — the  perpetual  work 
Of  THY  creation,  finished,  yet  renewed 
For  ever ! 


LECTURE   III. 

1.  Introductory  remarks.  2.  Substances  composing  the  crust  of  the 
globe.  3.  Crystallisation.  4.  Stratification.  5.  Inclined  and  vertical 
strata.  6.  Veins  and  faults.  7.  Chronological  arrangement  of  the 
strata.  8.  Tertiary  formations.  9.  Classification  of  the  tertiary  strata. 
10.  Fossil  shells.  11.  Mineralogical  characters  of  the  tertiary  system. 
12.  Newer  tertiary  or  pliocene  deposits.  13.  Crag  of  Norfolk  and 
Suffolk.  14.  The  Sub-Apennines.  15.  Middle  tertiary,  or  miocene 
deposits.  16.  Lower  tertiary,  or  eocene  deposits.  17.  The  Paris  basin. 
18.  The  London  basin.  19.  The  Isle  of  Sheppey.  20.  Fossil  fruits  of 
the  tertiary  strata.  21.  Upper  marine,  or  Bagshot  sand.  22.  Artesian 
wells.  23.  The  Hampshire  or  Isle  of  Wight  basin.  24.  Alum  bay. 
25  London  clay  of  the  Hampshire  basin.  26.  Fresh-water  strata  of  the 
Isle  of  Wight.  27.  Organic  remains  of  the  Paris,  London,  and  Hants 
basins.  28.  Fossil  plants  and  zoophytes.  29.  Tertiary  marine  and 
fresh-water  shells.  30.  Nummulites,  and  other  cephalopoda.  31.  Crus- 
tacea and  fishes.  32.  Fossil  birds.  33.  Fossil  animals  of  Paris.  34. 
Palaeotheria  and  anoplotheria.  35.  Fossil  quadrumana,  or  monkeys. 
36.  Tertiary  strata  of  Aix,  in  Provence.  37.  Fossil  insects.  38.  Lacus- 
trine formation  of  GEningen.  39.  Fossil  fishes  of  Monte  Bolca.  40. 
Tertiary  volcanoes  of  France.  41.  Extinct  volcanoes  of  Auvergne. 
42.  The  crater  of  Puy  de  Come.  43.  Mont  Dor.  44.  Fresh-water  lime- 
stone and  organic  remains  of  Auvergne.  45.  Summary  of  the  geological 
phenomena  of  Auvergne.  46.  Erosion  of  valleys  by  water-currents. 
47.  Extinct  volcanoes  of  the  Rhine.  48.  Brown  coal  formation.  49. 
Other  tertiary  strata  of  Europe,  North  America,  &c.  50.  Altered  ter- 
tiary strata  of  the  Andes.  51.  Tertiary  saliferous  deposit.  52.  Retro- 
spect. 53.  Concluding  remarks. 

1.  INTRODUCTORY  REMARKS. — It  is  my  object 
in  these  Lectures  to  present  a  general  view  of  the 
philosophy  of  Geology,  rather  than  enter  at  length 
on  the  nature  and  distribution  of  the  materials  of 
which  the  crust  of  our  globe  is  composed  ;  and  to 
render  the  details  of  geological  phenomena  subser- 


J  1.  INTRODUCTORY  REMARKS.  185 

vient  to  an  explanation  of  the  laws  which  the 
Divine  Author  of  all  things  has  established  for  the 
renovation,  maintenance,  and  government  of  the 
organic  and  inorganic  kingdoms  of  Nature.  Based 
as  Geology  is  upon  observations  of  the  various 
physical  changes  which  are  now  taking  place,  and 
on  investigations  of  the  natural  records  of  those 
changes,  in  periods  antecdent  to  all  human  history 
and  tradition,  the  rocks  and  mountains  are  the 
alphabet,  the  book  of  Nature  the  volume,  by  which 
the  student  of  this  interesting  department  of  science 
can  best  learn  its  important  lessons.  But  to  those 
who  cannot  examine  Nature  in  her  secret  recesses, 
or  accompany  an  experienced  teacher  to  the  valleys, 
or  the  mountain-tops,  lectures  illustrated  by  speci- 
mens and  drawings,  afford,  perhaps,  the  best  sub- 
stitute for  the  more  efficient  and  delightful  mode  of 
instruction. 

That  we  may  obtain  a  clear  and  comprehensive 
view  of  the  vast  field  of  inquiry  that  lies  open  before 
us,  artificial  classifications  are  necessary  in  this,  as  in 
other  departments  of  science  ;  and  without  assuming 
that  the  arrangement  in  which  the  various  deposits 
are  grouped  by  geologists,  will  not,  in  the  progress 
of  discovery,  require  considerable  modification,  it 
will  be  necessary,  as  an  introduction  to  the  subjects 
hereafter  to  be  discussed,  to  place  before  you  a 
tabular  view  of  the  formations  in  their  presumed 
chronological  order.  At  the  same  time  it  is  necessary 
to  bear  in  mind,  that  all  classifications  of  this  kind 


186  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

must  necessarily  involve  arbitrary  distinctions,  and 
that  very  possibly  it  will  hereafter  be  found  that 
we  may  in  some  instances  have  classed  as  general, 
what  may  prove  to  be  merely  local  phenomena ;  and 
have  grouped  together  deposits,  which  farther  in- 
vestigations may  show  to  be  distinct,  and  separated 
from  each  other  by  vast  periods  of  time.  This  con- 
sideration will  not,  however,  affect  those  leading 
principles  of  modern  Geology,  which  it  is  my  pre- 
sent endeavour  to  render  familiar  to  the  intelligent 
but  unscientific  inquirer. 

We  will  now  take  a  general  view  of  the  nature  of 
the  mineral  substances  which  enter  into  the  compo- 
sition of  the  crust  of  our  globe,  and  briefly  notice 
the  laws  which  regulate  the  deposition  of  detritus  in 
the  beds  of  lakes  and  rivers,  and  in  the  depths  of  the 
ocean.  But,  as  I  have  already  remarked,  it  is  not  my 
intention  to  enter  on  these  departments  of  Geology 
in  detail ;  the  works  of  Bakewell,*  Lyell,f  Phillips,  J 

*  "  Introduction  to  Geology,"  by  Robert  Bakewell,  Esq. 
1  vol.  8vo.  5th  edition.  This  excellent  volume  should  be  the 
first  book  in  the  library  of  the  geological  student. 

f  "  The  Principles  of  Geology,"  by  Charles  Lyell,  Esq. 
F.R.S.  4  vols.  12mo.  One  of  the  most  interesting  works  in 
the  English  language.  "  Elements  of  Geology."  1  vol.  By 
the  same  author.  1838. 

J  "  A  Guide  to  Geology,"  by  John  Phillips,  Esq.  RR.S. 
1  vol.  12mo.  The  article  on  Geology,  in  the  Encyclopedia 
Metropolitana,  by  the  same  excellent  writer,  is  in  my  opinion 
the  best  scientific  epitome  of  modern  Geology  that  has  yet 
appeared.  "  A  Treatise  on  Geology,"  in  2  vols.  foolscap  8vo. 
by  the  same  author.  1839.  A  work  of  great  merit. 


§  2.  CRUST  OF  THE  GLOBE.  187 

De  la  Beche,*  Burr,-)-  and  others,  afford  all  the 
information  on  these  subjects  which  the  student  can 
require. 

2.  SUBSTANCES  COMPOSING  THE  CRUST  OF  THE 
GLOBE. — Every  substance  .is  composed  of  atoms  of 
inconceivable  minuteness,  held  together  by  a  prin- 
ciple termed  attraction  or  cohesion,  and  which  is 
probably  a  modification  of  that  influence,  which, 
as  it  exists  under  other  conditions  in  inorganic 
substances,  is  called  electricity,  galvanism,  or  mag- 
netism ;  and  in  organized  beings,  nervous  influence. 
As  the  different  stages  of  solidity,  fluidity,  or  vapour, 
in  which  every  material  body  may  exist,  have  been 
exemplified  in  the  former  lectures,  we  need  only 
remark,  that  there  are  about  sixteen  substances, 
which  in  the  present  state  of  chemical  knowledge 
are  considered  simple  in  themselves,  and  which, 
in  their  various  combinations,  constitute  by  far 
the  largest  amount  of  the  gaseous,  liquid,  solid, 
organic,  and  inorganic  matter  of  the  earth.  Of 
these,  eight  are  non-metallic ;  viz.  oxygen,  hydrogen, 
nitrogen,  carbon,  sulphur,  chlorine,  fluorine,  and 
phosphorus.  There  are  also  six  metallic  bases 
of  alkalies  and  earths,  namely,  silicium,  alumine, 

*  "  A  Geological  Manual,"  by  H.  T.  De  la  Beche,  Esq. 
F.R.S.  An  admirable  work  of  reference.  "  Researches  in 
Theoretical  Geology."  A  volume  of  considerable  interest, 
affording  a  condensed  and  perspicuous  view  of  the  theories  of 
modern  geologists. 

f  "  Elements  of  Practical  Geology,"  by  Frederick  Burr,  Esq. 
1  vol.  foolscap  8vo. 


188  THE  WONDERS  OF  GEOLOGY.  LECT.  Ill- 

potassium,  sodium.,  magnesium,  and  calcium  ;  and 
two,  the  oxides  of  which  are  neither  earths  nor 
alkalies,  namely,  iron  and  manganese.  The  re- 
maining metallic  substances,  copper,  lead,  zinc, 
arsenic,  silver,  gold,  &c.  are  comparatively  unim- 
portant in  a  geological  point  of  view. 

The  common  sedimentary  rocks  are  in  a  great 
measure  composed  either  of  lime,  silex,  or  argilla- 
ceous earth;  and  they  possess,  what  in  rninera- 
logical  language  is  called,  a  cleavage,  or  peculiar 
fracture,  which  is  distinct  in  each.  Thus,  if  I  take 
a  flint  and  break  it  at  random,  you  perceive  that  it 
presents  a  glassy  or  conchoidal  fracture,  a  sharp 
cutting  edge;  and  subdivide  it  as  I  may,  it  still 
retains  the  same  character :  but  if  I  break  a  piece 
of  chalk,  the  edge  is  not  sharp  or  cutting,  but  blunt 
and  dull,  exhibiting  what  is  called  in  mineralogy  an 
earthy  fracture.  Again,  if  I  shiver  to  pieces  with 
my  hammer  this  calcareous  spar,  every  fragment 
presents,  more  or  less  distinctly,  a  rhomboidal  form ; 
so  true  is  the  remark,  that  we  cannot  break  a  stone 
but  in  one  of  nature's  joinings. 

3.  CRYSTALLIZATION. — Crystallization  may  be 
defined  a  methodical  arrangement  of  the  particles 
of  matter  according  to  fixed  laws.  For  instance — 
there  are  nearly  500  varieties  of  crystallized  car- 
bonate of  lime,  each  crystal  being  composed  of 
millions  of  atoms  of  the  same  compound  substances, 
and  having  one  invariable  primary  form — that  of 
a  rhomboid.  Mechanical  division  is  incapable  of 


§4.  STRATIFICATION.  189 

altering  this  arrangement ;  break  them  as  we  may, 
we  can  only  separate  them  into  a  rhomboidal  figure ; 
nor  can  this  condition  be  altered  except  by  chemical 
decomposition.  If  we  pursue  our  investigations 
yet  farther,  analysis  shows  that  every  atom  of  these 
crystals  consists  of  quicklime  and  carbonic  acid, 
which  are  each  made  up  of  innumerable  molecules. 
"  Lime  and  carbonic  acid  are  also  themselves  com- 
pounds, lime  being  composed  of  a  metal  called 
calcium  and  oxygen ;  and  carbonic  acid,  of  carbon 
and  oxygen.  Thus  these  ultimate  particles  of  cal- 
cium, carbon,  and  oxygen,  form  the  indivisible  atoms 
into  which  all  the  secondary  crystals  of  lime  may  be 
reduced."* 

4.  STRATIFICATION. — As  our  previous  investi- 
gations have  shown  that  the  disintegration  and 
solution  of  the  most  refractory,  and  apparently  in- 
destructible substances,  by  the  conjoined  effects  of 
mechanical  and  chemical  agency,  are  constantly  in 
progress,  we  can  at  once  proceed  to  the  consi- 
deration of  the  manner  in  which  the  spoils  of  the 
ancient  lands  and  seas  have  been  accumulated,  and 
converted  into  the  rocks  and  strata  of  existing 
islands  and  continents.  I  have  already  adverted 
to  the  formation  of  beach  and  sand,  and  the  depo- 
sition of  mud  and  clay  in  layers  or  strata,  and  their 
subsequent  consolidation  into  rocks.  And  here  let 
me  remind  you,  that  strata  are  the  successive  layerg 
or  accumulations  of  detritus,  spread  over  each 
*  Dr.  Bucklaud's  Bridgwater  Essay. 


190  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

other,  in  such  manner  as  to  allow  of  the  partial 
consolidation  of  one  bed,  before  it  is  covered  by  a 
deposition  of  the  materials  of  another  ;  and  a  rock 
is  said  to  be  stratified,  when  it  presents  the  appear- 
ance of  such  divisions.  The  chalk  cliffs,  and  the 
sandstone  quarries  in  the  south-east  of  England, 
afford  excellent  illustrations  of  this  structure.  The 
original  direction  of  these  layers  must  have  been 
more  or  less  horizontal,  for  this  obvious  reason, 
that  in  their  fluid,  or  semi-fluid  state,  they  would 
find  their  own  level,  and  spread  over  the  surface  of 
the  basin  into  which  they  flowed ;  and  although 
they  might  partake  of  the  inequalities  of  the  depres- 
sion in  which  they  were  deposited,  yet  this  cause 
would  not  affect  their  general  distribution.  The 
strata  when  accumulated  in  very  thin  layers,  re- 
sembling the  seams  formed  by  the  leaves  of  a  closed 
book,  are  termed  lamince  ;  and  this  character  very 
commonly  prevails  in  fluviatile  or  river  deposits: 
thus  the  shales,  clays,  and  sandstones,  of  Tilgate 
Forest  are  laminated,  and  often  bear  the  impress 
of  the  waters  which  have  meandered  over  them 
(see  pages  4-2,  43).  The  contemporaneous  beds 
formed  in  the  same  oceanic  basin,  however  they 
may  maintain  a  general  character  over  very  exten- 
sive areas,  must  nevertheless  vary  considerably.  At 
the  present  moment,  the  rivers  flowing  from  different 
latitudes  into  our  existing  seas,  must  necessarily  be 
producing  in  the  same  marine  basin  accumulations 
of  a  very  dissimilar  character ;  and  the  geographical 


$  5.  INCLINED  AND  VERTICAL  STRATA.  191 

distribution  of  the  detritus,  must  be  still  more 
affected  by  the  agency  of  those  powerful  currents, 
to  which  allusion  has  already  been  made  (page  55). 
Bearing  in  mind  these  elements  of  variation  in  the 
depositions  that  may  contemporaneously  take  place 
within  the  same  oceanic  basin,  we  shall  be  prepared 
to  find  similar  discrepancies  in  the  contents  of  the 
beds  of  the  ancient  seas. 

5.  INCLINED  AND  VERTICAL  STRATA.  —  But 
although  the  strata,  whether  accumulated  in  banks 
or  ridges,  or  deposited  in  basins  or  depressions, 
have  originally  been  consolidated  in  horizontal 
layers,  yet  this  arrangement  has  frequently  been 
disturbed  by  expansive  forces  from  below,  and  the 
strata  have  been  broken  up,  and  thrown  into  every 
direction,  from  a  slight  degree  of  inclination,  to  a 
vertical  position.  The  sections  before  us,  (Plates 
7,  8,  9,  10,)  to  which  I  shall  hereafter  have  occasion 
to  refer,  exhibit  strata  in  various  states  of  dis- 
placement. 

Although  it  is  my  wish  to  abstain  as  much  as 
posible  from  technical  language,  yet  as  it  cannot  in 
all  cases  be  avoided  without  much  circumlocution, 
it  will  be  convenient  in  this  place  to  explain  a  few 
scientific  terms  which  are  commonly  employed. 
Thus,  parallel  layers  or  strata,  piled,  as  it  were, 
horizontally  upon  each  other,  as  or,  i,  c,  c?,  in  the 
following  diagram  (and  in  the  Section  near  Devizes, 
Plate  9,  No.  II.)  are  said  to  be  conformable ;  but 
when  strata  are  superimposed  on  others  which  lie 


192 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


in  a  different  direction,  as  the  series  a,  b,  c,  d,  on  the 
beds  e,f,g,h,  (or  in  the  natural  section,  Plate  9, 
No.  III.)  as  if  a  set  of  horizontal  volumes  were 


h  h 

TAB.  32.— STRATIFICATION. 

placed  flat  on  the  inclined  edges  of  another  series 
of  books,  they  are,  in  geological  language,  in  an 
unconformable  position. 

6.  VEINS  AND  FAULTS. — But  not  only  have  the 
strata  suffered  change  of  position  from  the  disturb- 
ing causes  which  we  have  shown  are  still  in  actual 
operation ;  they  have  also  been  rent  and  broken  up, 
and  exhibit  cracks  or  fissures,  which  in  rocks  near 
the  surface  are  sometimes  filled,  as  we  have  already 
noticed,  with  bones,  pebbles,  and  stalactitical  con- 
cretions (page  178) ;  and  in  those  of  more  ancient 
epochs,  with  eruptions  of  melted  matter,  and  veins  of 
metalliferous  ores.  The  term  fault  is  applied  to  those 
fractures  and  displacements  of  the  strata  which  are 


§  7.  VEINS  AND  FAULTS.  193 

accompanied  with  the  subsidence  of  one  part  of  a 
mass  and  the  elevation  of  another.  This  is  exem- 
plified in  the  section  of  the  carboniferous  strata, 
(Tab.  32,  e,f,  g>  h,)  where  the  layers,  or  seams  of 
coal,  have  been  shifted  to  a  higher  level,  although 
both  sides  of  the  rock  remain  in  apposition  ;  f  marks 
the  line  of  fault,  Stratification,  in  fact,  may  be 
compared  with  the  operation  of  erecting  a  building  ; 
strata  of  clay  being  comparable  to  beds  of  mortar, 
those  of  harder  rocks  to  layers  of  brick ;  while  the 
fissures,  veins,  and  faults  are  analogous  to  the  cracks, 
sinkings,  and  displacements  produced  by  the  settling 
of  different  portions  of  the  whole  edifice. 

7.  CHRONOLOGICAL  ARRANGEMENT  OF  THE 
STRATA. — In  the  ancient  alluvial  beds  of  gravel, 
sand,  and  marl,  containing  the  remains  of  gigantic 
mammalia,  which  formed  the  principal  subject  of 
the  last  lecture,  but  few  indications  of  stratification 
occur ;  those  deposits,  for  the  most  part,  bearing 
the  character  of  materials  transported  by  the  sea 
or  by  river  currents,  or  accumulated  in  estu- 
aries, and  thrown  up  in  bays  and  creeks  by  the 
waves,  rather  than  that  of  tranquil  depositions. 
The  formations  which  succeed,  we  shall  find  com- 
posed of  regularly  stratified  rocks,  but  interspersed 
here  and  there  with  alluvial  debris.  The  plan  of 
the  strata  before  you  (Plate  7)  is  intended  to  pre- 
sent a  general  view  of  the  various  systems  of  rocks, 
from  the  most  recent  to  the  most  ancient.  For 
more  detailed  explanations  and  sections,  reference 
o 


194  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

may  be  made  to  the  works  already  noticed ;  and 
particularly  to  the  admirable  systematic  diagram 
of  the  formations,  by  that  veteran  geologist,  IVlr. 
Webster,  which  forms  the  frontispiece  of  Dr.  Buck- 
land's  Bridgewater  Essay. 

It  will  here  be  necessary  to  premise,  that  there 
are  three  elements  of  classification  applicable  to 
stratified  rocks;  namely,  1st,  their  mineral  struc- 
ture ;  2dly,  their  order  of  superposition  ;  and  3dly, 
the  nature  of  the  organic  remains  which  they  con- 
tain :  the  following  arrangement  is  in  accordance 
with  these  principles.* 

CHRONOLOGICAL   ARRANGEMENT   OF  THE 
STRATA. 

Commencing  with  the  uppermost  or  newest  Deposits. 

FOSSILIFEROUS    STRATA. 

I.  MODERN  AND  ANCIENT  ALLUVIUM. — Comprising  the  modern 
and  ancient  superficial  deposits,  described  in  the  previous 
lectures.     The  modern  are  characterised  by  the  remains  of 
man  and  contemporaneous  animals  and  plants  ;  the  ancient, 
by  an  immense  proportion  of  large  mammalia  and  carnivora, 
of  species  and  genera,  both  recent  and  extinct. 

II.  THE  TERTIARY  SYSTEM. — An  extensive  series,  comprising 
groups  of  marine  and  lacustrine  deposits,  characterised  by 
the  remains  of  animals  and  vegetables,  the  greater  portion 
of  which  are  extinct.     Volcanoes  of  great  extent  were  in 
activity  during  this  epoch. 

*  See  Professor  Sedgwick's  Synopsis  of  the  English  Series  of  Stratified 
Rocks  inferior  to  the  old  Red  Sandstone.  Proceedings  of  the  Geological 
Society,  vol  ii.  p.  76. 


§7.  ARRANGEMENT  OF  THE  STRATA.  IQj 

SECONDARY  FORMATIONS. 

III.  THE  CHALK,  or  CRETACEOUS  SYSTEM. — A  marine  forma- 
tion, comprising  beds  of  limestone,  sandstone,  marl,  and 
clays,  abounding  in  remains  of  zoophytes,  mollusca,  cephalo- 
poda, echinodermata,  fishes,  &c. ;  drifted  wood,  and  marine 
plants  ;  with  crocodiles,  turtles,  and  extinct  reptiles. 

IV.  THE  WEALDEN. — Comprising  the  weald  clay,  the  strata  of 
Tilgate  Forest,  and  of  Hastings,  and  the  limestones  and 
clays  of  Purbeck.     A  freshwater  formation,  evidently  the 
delta  of  some  ancient  river ;  characterised  by  an  abundance 
of  the  remains  of  enormous  and  peculiar  reptiles,  namely, 
the  iguanodon,  hylaeosaurus,  megalosaurus,   plesiosaurus, 
crocodile,  &c. ;   of  terrestrial  plants,  freshwater  mollusca, 
and  birds. 

V.  THE  OOLITE A  marine  formation  of  vast  extent,  consist- 
ing of  limestones  and  clays,  abounding  in  marine  shells, 
corals,   fishes,  and  reptiles,   both  terrestrial  and  marine. 
Land  plants  of  peculiar  species,  and  the  remains  of  two  or 
more  genera  of  MAMMALIA. 

VI.  THE  LIAS. — A  series  of  clays,  shales,  and  limestones,  with 
marine  shells,  cephalopoda,  crinoidea,  and  fishes.    Reptiles, 
particularly  of  two   extinct  genera,   the  plesiosaurus  and 
ichthyosaurus,   in  immense   numbers.      Drifted  wood  and 
plants. 

VII.  THE  SALIFEROUS,  or  NEW  RED  SANDSTONE  SYSTEM. — 
Comprising    marls,   sandstones,    and   conglomerates,   fre- 
quently of  a  red  colour,  with  shells,  corals,  and  plants ; 
fishes  and  reptiles.     This  series  forms  the  grand  depository 
of  rock- salt 

VIII.  THE  CARBONIFEROUS,  or  COAL  SYSTEM. — Shales,  iron- 
stones, millstone  grit,  freshwater  limestone,  and  immense 
beds  of  coal.     This  system  is  characterised  by  innumerable 
remains  of  land  and  aquatic  plants,  of  a  tropical  character, 
and  belonging  to  extinct  species  and  genera;  with  fishes, 
reptiles,  and  insects. 

o2 


196  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

IX.  THE  OLD  RED  SANDSTONE  SYSTEM.* — Consisting  of  various 
strata  of  conglomerate,  sandstone,  marl,  and  limestone  ;  the 
prevailing  colour  of  a  chocolate  red ;  contains  shells,  corals, 
and  fishes,  many  of  which  are  peculiar. 

X.  THE  SILURIAN  SYSTEM.— Composed  of  marine  limestones, 
shales,    sandstones,   and    calcareous  flags ;    abounding  in 
shells,   many  of  new  forms ;    and  swarming  with   corals, 
crinoidea,  and  trilobites. 

XI.  THE  CAMBRIAN,  or  GRAUWACKE  SYSTEM. — Consists  prin- 
cipally of  a  largely  developed  series  of  slate  rocks  and  con- 
glomerates, containing  shells  and  corals. 

METAMORPHIC  ROCKS. 
Destitute  of  Organic  Remains. 

Stratified. 

XII.  THE  MICA  SCHIST. — Sedimentary  rocks,  altered  by  high 
temperature ;  mica  slate,  quartz  rock,  crystalline  limestone, 
gneiss,  and  hornblende  schist,  &c.,  exhibiting  no  traces  of 
organic  remains. 

XIII.  THE  GNEISS  SYSTEM. — Formed  of  gneiss,  sienite,  and 
quartz  rock,  alternating  with  clay  slate,  mica  schist,  &c. 

Unstratified. 

XIV.  GRANITE. — In  amorphous  masses  and  veins ;  porphyry, 
serpentine,  trap,  &c. 

The  proportionate  thickness  of  the  rocks  hitherto 
examined  in  England  is  estimated  as  follows  ;•(•  but 

*  Fide  "  Geology  of  the  Silurian  Region,"  2  vols.  4to.  with 
numerous  plates  and  map,  by  Roderick  Impey  Murchison,  Esq. 
V.P.G.S.  The  most  splendid  and  important  work  on  British 
Geology  that  has  yet  appeared. 

f  Professor  Phillips. 


§8.  TERTIARY  FORMATIONS.  197 

the  statement  must  be  viewed  only  as  an  approxi- 
mative calculation. 

Tertiary  system         ....       2,000  feet. 

Cretaceous 1,100     „ 

Oolitic  and  lias 2,500     „ 

Saliferous 2,000     „ 

Carboniferous 10,000     „ 

Old  red  sandstone     ....       9,000*  „ 

Primary  rocks 20,000     „ 

I  have  represented  in  this  diagram  (Plate  7)  in- 
trusions of  the  ancient  melted  rocks,  as  serpentine, 
porphyry,  trap,  and  granite,  into  the  sedimentary 
strata ;  and  metalliferous  and  granitic  veins  in  the 
granite,  to  which  I  shall  hereafter  have  occasion 
to  refer.  At  present  it  will  only  be  necessary  to 
mention,  that  the  leading  features  of  this  arrange- 
ment may  be  recognised  in  every  considerable  extent 
of  country  throughout  the  world  ;  but  the  sub- 
divisions are  more  local,  and  cannot  be  generally 
maintained,  for  reasons  which  must  be  sufficiently 
obvious,  after  what  has  already  been  advanced. 
From  this  general  view  of  the  physical  records  of 
the  mutations  which  the  crust  of  our  globe  has 
undergone,  we  learn  how  numerous  and  important 
are  the  phenomena  comprised  within  the  sphere  of 
geological  inquiry,  and  how  vain  is  the  attempt  to 
offer  more  than  an  epitome  of  its  wonders  in  the 
brief  space  allotted  to  a  popular  course  of  lectures. 

8.  TERTIARY  FORMATIONS.  —  We  now  enter 
*  Mr.  Murchison. 


198  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

upon  the  consideration  of  the  tertiary  formations, 
those  deposits  of  the  seas,  rivers,  and  lakes,  which 
are  referable  to  the  period  immediately  antecedent 
to  the  existence  of  the  mammoth  and  mastodon, 
and  subsequent  to  the  deposition  and  consolidation 
of  the  chalk.  The  discoveries  of  MM.  Cuvier  and 
Brongniart,  about  twenty  years  since,  in  the  imme- 
diate vicinity  of  Paris,  first  directed  the  attention 
of  geologists  to  the  important  series  of  strata  which 
is  now  distinguished  by  the  name  of  tertiary  (see 
p.  18).  The  animals  whose  fossil  bones  abound  in 
the  gypsum  quarries  of  Montmartre,  and  belong  to 
extinct  genera  of  mammalia,  were  by  the  genius  of 
Cuvier,  again,  as  it  were,  called  into  existence,  and 
the  philosophers  of  Europe  saw  with  astonishment, 
whole  tribes  of  unknown  and  extraordinary  types 
of  being,  disinterred  from  rocks  and  mountains, 
which  had  hitherto  been  considered  as  possessing 
no  scientific  interest.  Analogous  strata,  some  of  a 
marine,  and  others  of  a  lacustrine  or  fluviatile  cha- 
racter, have  since  been  discovered  in  numerous 
localities  in  the  continents  of  Europe  and  America, 
forming  a  series  so  extensive,  and  requiring  such  a 
lapse  of  time  for  its  production,  that  the  chalk, 
hitherto  considered  as  comparatively  modern,  is 
carried  back  to  a  period  of  immense  geological  an- 
tiquity. The  tertiary  system  may  be  said  to  con- 
stitute a  series  of  formations  which  link  together 
the  present  and  the  past ;  for  while  the  most  ancient 
contain  organic  remains  related  to  those  of  the 


§  9.         CLASSIFICATION  OF  THE  TERTIARY  STRATA.       199 

secondary  formations,  the  most  recent  insensibly 
glide  into  the  modern  deposits,  and  contain  remains 
of  many  existing  species  of  animals  and  plant?, 
associated  with  forms  that  are  now  blotted  out  for 
ever.  Mr.  Lyell  has  adopted  a  classification  of  the 
tertiary  strata,  founded  on  the  proportion  of  recent 
species  of  animals  which  they  contain ;  and  as  shells 
occur  in  many  of  the  strata  in  great  abundance, 
and  in  an  excellent  state  of  preservation,  those  types 
of  animal  organization  have  been  selected  for  the 
distinctive  characters  of  the  subdivisions  into  which, 
for  the  convenience  of  study,  he  separates  these 
deposits.  In  the  present  state  of  our  knowledge, 
this  arrangement  is  of  great  utility,  but  it  appears 
probable  that  it  may  require  considerable  modifica- 
tion, or,  perhaps,  hereafter  be  altogether  abandoned 
with  the  progress  of  geological  research ;  for  it 
cannot  be  doubted,  that  strata  in  which  no  recent 
species  have  yet  been  found,  may  yield  them  to 
more  accurate  and  extended  observations. 

9.  CLASSIFICATION  OF  THE  TERTIARY  STRATA. 
— According  to  this  classification  the  tertiary  system 
forms  four  principal  groups,  each  of  which  is  cha- 
racterised by  the  relative  proportion  of  recent  and 
extinct  species  of  shells  which  it  contains ;  and  a 
nomenclature  has  been  adopted  to  denote  the  cha- 
racters upon  which  the  arrangement  is  founded. 
These  divisions  are  as  follow : — 

1.    THE    PLIOCENE     (signifying    more   new   or 
recent). — Tertiary  strata,  in  which  the  shells  are  for 


200  THE  WONDERS  OF  GEOLOGY.  LJECT.  III. 

the  most  part  recent,  with  about  ten  per  cent,  of 
extinct  species ;  these  beds  are  subdivided  into  the 
newer  and  older  pliocene. 

2.  THE  MIOCENE   (denoting  less  recent). — Con- 
taining a  small  proportion,  about  twenty  per  cent., 
of  recent  species  of  shells. 

3.  EOCENE   (signifying  the   dawn  of  recent,  in 
allusion  to  the  first  appearance  of  recent  species). — 
Containing  very  few  recent  species,  perhaps  not 
more  than  three  or  four  per  cent. 

The  marine  are  associated  with  a  like  number  of 
freshwater  formations,  and  the  general  characters 
of  the  tertiary  system  are  alternations  of  marine 
with  lacustrine  strata.  The  districts  occupied  by 
these  beds  in  Europe,  are  exceedingly  variable  in 
extent,  as  Mr.  Lyell  has  shown  in  a  very  ingenious 
map  of  the  tertiary  seas  ;*  and  it  appears  certain, 
that  during  the  epoch  of  their  formation,  there  were 
areas  which  were  alternately  the  sites  of  freshwater 
lakes  and  .inland  seas,  and  that  these  changes  were 
dependent  on  oscillations  in  the  relative  level  of  the 
land  and  water. 

10.  FOSSIL  SHELLS.  —  The  geological  evidence 
afforded  by  the  remains  of  animals  and  plants  has 
already  been  fully  exemplified;  but  our  remarks 
have  hitherto  in  a  great  measure  been  confined  to 
the  fossilized  skeletons  of  terrestrial  quadrupeds  ; 
the  shells  of  mollusca,  however,  from  their  dura- 
bility, often  escape  obliteration  under  circumstances 
*  Mr.  LyelPs  Principles  of  Geology,  vol.  i.  p.  214. 


§  10.  FOSSIL  SHELLS.  201 

in  which  all  traces  of  the  higher  orders  of  animals 
are  lost.  In  loose  sandy  strata,  they  occur  in  a  high 
degree  of  perfection ;  in  mud  and  clay,  in  a  fragile 
state ;  in  some  instances  they  are  silicified  ;  and 
many  limestones  are  wholly  composed  of  their  re- 
mains, cemented  together  by  calcareous  matter. 
Molluscous  animals*  are  divided  into  mollusca, 
properly  so  called,  which  are  covered  with  a  shell, 
as  snails,  periwinkles,  &c. ;  and  conc/[ifera,-\-  having 
a  shell  with  two  valves,  as  the  oyster,  scallop,  &c. 
The  former  are  of  a  higher  organization  than  the 
latter,  having  eyes,  and  a  distinct  nervous  system  ; 
the  latter  have  neither  eyes  nor  head,  and  are  there- 
fore called  acephala.~^  Some  genera  of  mollusca 
are  herbivorous,  living  exclusively  on  vegetables  ; 
others  are  carnivorous ;  and  many  have  a  retractile 
proboscis,  furnished  with  a  rasp,  by  which  they  can 
perforate  wood,  shells,  stone,  and  other  substances. 
The  shells  of  the  carnivorous  testacea  are  also 
generally  provided  with  a  channelled  or  grooved 
beak  for  the  reception  of  the  fleshy  syphon  by  which 
the  sea  water  is  conveyed  to  the  respiratory  organs 
(Tab.  38.  Fig.  3,  4,  5);  while  the  herbivorous  have 
the  opening  of  the  shell  entire  (Tab.  39,  Fig.  3, 
5,  6,  7).  Some  tribes  are  exclusively  marine, 
others  live  only  in  fresh-water,  while  many  are  re- 
stricted to  the  brackish  waters  of  estuaries.  Their 
geographical  distribution  is  alike  various :  certain 

v    *  Soft-bodied  animals.  f  Shell-bearing  animals. 

J  Having  no  head. 


202  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

forms  (the  cephalopoda)  inhabit  deep  waters  only, 
and  are  provided  with  an  apparatus  by  which  they 
can  rise  to  the  surface ;  while  others  are  littoral, 
that  is,  live  only  in  the  shallows  along  the  sea 
shores ;  many  exist  in  quiet,  others  in  turbulent 
waters  ;  some  are  gregarious,  like  the  oyster,  while 
others  occur  singly  or  in  small  groups.  All  these 
varieties  of  condition  are  more  or  less  strongly 
impressed  on  their  shelly  coverings,  which  may 
be  considered  as  their  external  skeletons ;  and  the 
experienced  conchologist  is  enabled  by  the  pecu- 
liar characters  of  the  shell,  at  once,  to  determine 
the  economy  and  habits  of  the  animal,  and  con- 
sequently the  physical  conditions  in  which  it  was 
placed.*  In  this  point  of  view,  fossil  shells  become 
objects  of  the  highest  importance  to  the  geologist, 
since  they  are  frequently  the  only  records  of  the 
former  condition  of  our  planet.  But  I  must  return 
from  this  digression,  and  proceed  to  the  consider- 
ation of  the  phenomena  presented  by  the  several 
groups  of  the  tertiary  formations. 

11.  MlNERALOGICAL  CHARACTERS  OF  THE  TER- 
TIARY SYSTEM. — The  predominating  characters  of 
the  tertiary  system,  as  I  have  already  mentioned,  are 
alternations  of  marine  beds  with  those  of  lacustrine 
and  freshwater  origin.  A  large  proportion  of  the 
strata  is  arenaceous,  having  intervening  clays  and 
marls.  Shingles,  the  remains  of  ancient  sea- 

*  See  an  interesting  paper  on  Shells,  by  Mr.  Gray,  of  the 
British  Museum.  Philosophical  Transactions. 


§  11.          CHARACTERS  OF  THE  TERTIARY  SYSTEM.          203 

beaches,  abound  in  some  localities,  and  form  either 
a  conglomerate  or  puddingstone,  as  that  of  Hert- 
fordshire (page  88) ;  or  a  ferruginous  breccia,  as  at 
Castle  Hill,  near  Newhaven,  on  the  Sussex  coast. 
The  ruins  of  the  chalk  are  everywhere  recognisable 
in  the  beds  of  water-worn  flints,  which  contain  shells 
and  zoophytes  peculiar  to  the  cretaceous  system. 
Large  boulders  of  sandstone  are  of  frequent  occur- 
rence, and  may,  perhaps,  be  referred  to  the  newest 
beds  of  the  series.  In  the  vicinity  of  Brighton, 
blocks  of  ferruginous  breccia  are  scattered  over  the 
surface  of  the  Downs,  and  masses  of  quartzose  sand- 
stone, of  a  saccharine  structure,  are  seen  at  Falmer, 
and  in  Stanmer  Park :  a  remarkable  rock  of  this 
kind  formerly  existed  in  Goldstone  Bottom,  near 
Brighton,  but  is  now  destroyed.  In  most  of  the 
gravel  beds  around  London  there  are  numerous 
blocks  of  silicious  breccia  and  conglomerate,  of 
which  there  are  many  of  considerable  magnitude 
on  the  grounds  of  John  Allnutt,  Esq.  of  Clapham 
Common.  In  some  of  the  tertiary  formations, 
limestone  predominates,  and  alternates  with  sands 
and  marls  of  great  variety  and  brilliancy  of  colour ; 
beds  of  gypsum,  and  silicious  nodules  closely  re- 
sembling the  flints  of  the  chalk,  also  occur.  Such 
are  the  general  features  of  this  system  of  deposits, 
which  I  shall  now  examine  more  in  detail. 

The  distribution  of  the  tertiary  strata  over 
Europe,  appears  to  be  in  areas  more  or  less  well 
defined ;  in  our  own  island,  there  are  the  basins  of 


204  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

London  and  Hampshire,  and  the  remains  of  other 
beds  in  Yorkshire,  and  in  Norfolk  and  Suffolk.  In 
France,  the  metropolis  is  situated  within  the  con- 
fines of  a  tertiary  basin ;  and  in  the  south  and  north 
of  that  country,  extensive  tracts  are  formed  of  these 
deposits ;  in  Auvergne,  where  they  are  associated 
with  ancient  volcanic  eruptions,  they  constitute  a 
district  of  unrivalled  geological  interest.  In  the 
Sub- Apennines,  they  are  largely  developed ;  and 
in  other  parts  of  Sicily  and  Italy  they  insensibly 
pass  into  vast  beds,  which  are  still  in  progress  of 
formation. 

12.  NEWER  TERTIARY,  OR  PLIOCENE  DEPOSITS. 
— From  the  large  proportion  of  recent  species  of 
shells  which  occur  in  some  of  the  pliocene  strata, 
the  beds  have  the  appearance  of  a  modern  aggre- 
gate, as  the  extensive  and  beautiful  collection  from 
Palermo,  before  us  (for  which  I  am  indebted  to  the 
kindness  of  the  Marquis  of  Northampton,  P.R.S.) 
well  displays.  A  low  range  of  hills,  rising  to  an 
elevation  of  about  200  feet  above  the  level  of  the 
Mediterranean,  immediately  behind  Palermo,  is  in 
a  great  measure  constituted  of  coarse  limestone, 
formed  of  friable  shells,  which  are  frequently  in 
an  admirable  state  of  preservation  ;  white  and 
brittle  in  general,  but  in  some  examples  preserving 
their  markings  and  natural  polish.  The  elegant 
and  picturesque  manner  in  which  they  are  occa- 
sionally grouped  together,  renders  them  objects  of 
great  beauty  and  interest.  These  shells,  with  but 


§  12.  NEWER  TERTIARY  DEPOSITS.  205 

very  few  exceptions,  belong  to  species  still  living 
in  the  adjacent  seas;  a  proof  that  when  the  lime- 
stone was  formed,  the  same  condition  of  the  basin 
of  the  Mediterranean  existed  as  at  present,  and 
continued  uninfluenced  by  the  elevation  of  this 
portion  of  its  ancient  bed.  In  other  parts  of  Sicily, 
limestone,  blue  marl,  with  shelly  calcareous  breccia, 
and  gypseous  clay,  intermingled  with  volcanic  pro- 
ducts, occur.  The  Val  di  Noto  is  particularly 
mentioned  by  Mr.  Lyell,  as  presenting  a  remark- 
able assemblage  of  deposits ;  *  and  I  will  quote 
his  lucid  and  highly  graphic  description.  "  The 
rising  grounds  of  the  Val  di  Noto  are  separated 
from  the  cone  of  Etna,  and  the  marine  strata  on 
which  it  rests,  by  the  plain  of  Catania,  which  is 
elevated  above  the  level  of  the  sea,  and  watered  by 
the  Simeto.  The  traveller  passing  from  Catania 
to  Syracuse,  by  way  of  Sortina  and  the  valley  of 
Pentalica,  may  observe  many  deep  sections  of  these 
modern  formations,  which  rise  into  hills  from  one 
to  two  thousand  feet  in  height,  entirely  composed 
of  sedimentary  strata,  with  recent  shells ;  these  are 
associated  with  volcanic  rocks.  Tlie  whole  series 
of  strata,  exclusively  of  the  volcanic  products, 
is  divisible  into  three  principal  groups.  1.  The 
uppermost,  compact  limestone  in  laminated  strata, 
with  recent  shells ;  total  thickness,  from  700  to 
800  feet.  2.  Calcareous  sandstone,  with  schistose 
limestone.  3.  Laminated  marls  and  blue  clays." 
*  Principles  of  Geology,  vol.  iii.  p.  388. 


206  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

The  above  groups  contain  shells  and  zoophytes  of 
the  same  species  as  those  from  Palermo  which  I 
have  just  noticed.  The  large  scallop  or  pecten 
(Pecten  jacobceus),  which  at  the  present  day  is  pro- 
fusely strewn  on  the  Sicilian  shores,  is  also  beau- 
tifully preserved,  and  abundant  in  the  compact 
limestone.  Leaves  of  plants  and  stems  of  reeds, 
are  of  common  occurrence. 

13.  CRAG  OF  NORFOLK  AND  SUFFOLK. — On  the 
eastern  coasts  of  Essex,  Norfolk,  and  Suffolk,  beds 
of  sand  and  gravel,  abounding  in  shells  and  corals, 
are  superposed  on  the  blue  clay  lying  on  the  chalk, 
and  are  distinguished  by  the  name  of  Crag,  a 
provincial  term  signifying  gravel.  The  late  Mr. 
Parkinson  first  described  these  strata,  and  in  the 
"Organic  Remains  of  a  Former  World,"*  figured 
a  shell  which  was  formerly  in  much  request  among 
collectors,  the  Essex  reversed  whelk  (Fusus  con- 
trarius),  in  which  the  spiral  convolutions  pass  from 
right  to  left,  instead  of  in  the  opposite  and  ordinary 
direction.  Here  are  several  beautiful  examples  of 
this  fossil,  collected  by  Sir  Woodbine  Parish  ;  they 
all  have  the  deep  ferruginous  colour  which  so  com- 
monly prevails  in  the  fossils  of  the  Crag.  The 
Crag  first  appears  at  Walton  Nase,  in  Essex,  and 
constitutes  the  upper  part  of  the  cliffs  on  both  sides 
of  Hanwell,  varying  from  a  few  feet  to  thirty  or 
forty  in  thickness.  It  extends  inland  along  the 
Suffolk  'and  Norfolk  coast,  forming  a  tract  of  at 
*  Vol.  iii.  pi.  6.  fig.  5. 


§  IS.  CRAG  OF  NORFOLK  AND  SUFFOLK.  207 

least  forty  miles  in  length ;  near  Ipswich  it  is 
spread  over  a  considerable  area,  and  abounds  in 
shells  and  other  marine  exuviae.  The  fossils  which 
I  now  place  before  you  are  from  collections  made 
by  the  late  Mrs.  E.  Cobbold,  of  Holywell  Park, 
near  Ipswich  ;  Sir  Woodbine  Parish  ;  the  late 
Samuel  Woodward,  Esq.;*  and  Edward  Charles- 
worth,  Esq.,  whose  recent  investigations  have 
thrown  much  light  on  the  zoological  characters  of 
these  deposits.  The  Crag  is  divided  into  two 
groups ;  the  lowermost,  or  coralline  Crag,  which 
is  composed  of  loose  sand,  and  abounds  in  corals, 
sponges,  and  shells,  in  so  perfect  a  state  as  to 
indicate  that  they  lived  and  died  on  the  spot  where 
their  remains  are  entombed.  This  series  is  upwards 
of  fifty  feet  in  thickness,  and  rests  upon  a  layer  of 
blue  clay,  which  will  hereafter  be  noticed.  The 
uppermost,  or  Red  Crag,  so  called  from  its  deep 
ferruginous  colour,  consists  of  sand  with  shells 
which  are  generally  broken  and  water-worn  ;  the 
Norfolk  Crag  appears  to  be  principally  composed 
of  these  upper  beds.  The  fossils  of  the  Crag  are 
extremely  numerous ;  they  consist  of  several  hun- 
dred species  of  marine  shells,  some  of  extinct,  but 
the  greater  part  of  species  now  existing  in  the 
German  Ocean ;  of  corals,  sponges,  and  more  than  a 
hundred  species  of  microscopic  foraminifera ;  with 
teeth  and  scales  of  fishes.  The  collection  of  Crag 
shells  on  the  table  was  some  years  since  examined 
*  Author  of  "  Outlines  of  the  GEOLOGY  of  NORFOLK." 


208  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

by  Mr.  Lyell,  and  M.  Deshayes,  a  distinguished 
French  naturalist,  by  whom  more  than  half  the 
species  were  considered  to  be  of  extinct  forms; 
and  the  remainder  identical  with  species  which  now 
inhabit  the  German  Ocean.* 

14.  THE    SUB-APENNINES. — The    Apennines, 
that   chain    of    hills   which    extends   through    the 
Italian  peninsula,  are  flanked,  both  on  the  side  of 
the  Adriatic  and  the  Mediterranean,  by  the  Sub- 
Apennines,  a  low  range  composed  of  tertiary  marls, 
sands,    and    conglomerates,    abounding   in    marine 
shells  of  those  species  and  genera  which  prove  that 
some  of  the  strata  were  cotemporaneous  with  the 
Crag,  and  that  others  are  referable  to  a  more  an- 
cient epoch.     These  beds  have  resulted  from  the 
waste   of    the    secondary   rocks,    which    form   the 
Apennines,  and  were  dry  land  before  those  strata 
were  deposited. -j- 

15.  MIDDLE  TERTIARY,  OR  MIOCENE  DEPOSITS. 
—In  the  classification  of  Mr.  Lyell,  the  term  Mio- 
cene designates  those  tertiary  beds  in  which  recent 
species  of  shells  occur,  but  in   a  much  less  pro- 
portion  than  in    the   preceding    division ;    seldom 
amounting   to  one-fifth   of  the    whole.     As   there 
are  no  good  types  of  this  group  in  Great  Britain, 
I  shall  merely  observe,  that  marine  and  fresh-water 

*  Principles  of  Geology,  vol.  iv.  p.  71. 

f  Brocchi,  an  eminent  Italian  naturalist,  published  many 
years  since  a  valuable  work  on  the  fossil  shells  of  the  Sub- 
Apennines. 


§  16.          LOWER  TERTIARY,  OR  EOCENE  DEPOSITS.          209 

deposits  possessing  the  characters  here  defined 
occur  near  Bordeaux  and  Montpellier ;  and  in 
Piedmont,  Styria,  Hungary,  and  other  parts  of  the 
European  continent ;  but  in  many  instances  the 
strata  seem  to  merge  into  one  or  other  term  of 
the  series.  I  proceed  therefore  to  the  consideration 
of  the  Eocene,  or  those  tertiary  strata  which  are 
of  the  highest  antiquity,  and  are  found  deposited 
in  basins  or  depressions  of  the  chalk,  where  that 
formation  constitutes  the  fundamental  rock  of  the 
country.  Every  step  of  our  progress  will  now  be 
replete  with  the  deepest  interest,  and  new  and 
singular  forms  of  being  will  appear  before  us.  I 
shall  pass  rapidly  over  the  stratigraphical  character 
of  these  rocks,  that  our  attention  may  be  more  fully 
directed  to  the  extraordinary  organic  remains  which 
they  inclose. 

16.  LOWER  TERTIARY,  OR  EOCENE  DEPOSITS. — 
I  propose,  in  the  first  place,  to  describe  the  geo- 
graphical distribution  and  general  characters  of  a 
few  principal  groups  of  the  older  tertiary  strata; 
secondly,  to  investigate  the  nature  of  the  more 
remarkable  fossil  animals  and  plants  ;  and  lastly,  to 
survey  those  regions  of  central  France,  of  the  Rhine, 
and  of  South  America,  which  have  been  the  scenes 
of  active  volcanoes  during  the  tertiary  epoch. 

It  may   be  regarded  as  a  singular  coincidence, 

that  the  capitals  of  Great  Britain  and  France  are 

located  on  strata  of  the  same  geological    epoch. 

Paris  is  situated   on  a  vast  alternation  of  marine 

p 


210  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

and  fresh-water  beds,  lying  in  a  depression  of  the 
chalk ;  the  latter  forming  the  boundary  of  the  area 
in  which  the  city  is  placed.  London  is  built  on 
clays,  sands,  and  shingles,  also  filling  up  a  basin  of 
the  chalk,  which  skirts  the  area  of  the  tertiary  strata 
o"n  the  south,  but  is  open  to  the  sea  on  the  east.  In 
Hampshire,  a  series  of  contemporaneous  lacustrine 


TAB.  S3.— TERTIARY  BASINS  OF  PARIS,  LONDON,  AND  HANTS. 
(From  Mr.  Webster's  Map  in  the  Geological  Transactions.) 

deposits,  with  interspersions  of  marine  remains,  in 
like  manner  rest  upon  the  chalk,  and  constitute  the 
basin  of  the  Isle  of  Wight.  The  relative  situation 
and  comparative  extent  of  these  three  groups  are 
shown  in  the  map  (Tab.  33),  reduced  from  that 


§  17.  THE  PARIS  BASIN.  211 

which  accompanied  Mr.  Webster's  first  announce- 
ment of  the  characters  of  the  British  tertiary  for- 
mations; and  this  section,  by  Mr.  Lyell  (Tab.  34-), 
from  Hertfordshire  across  the  British  Channel,  to 
Sens  in  France,  explains  the  position  of  the  London 
and  Paris  basins,  and  the  underlying  secondary 
formations. 

Valley  of  Bray.          PARIS. 


3  3 

TAB.  34.— SECTION  FROM  HERTS,  TO  SENS,  IN  FRANCE. 

(From  Ly ell's  Elements  of  Geology.) 

1.   Chalk.      2.    Green  sand.      3.   Wealden. 

The  shaded  sites  of  London  and  Paris  indicate  the  tertiary  deposits. 

17.  THE  PARIS  BASIN.  —  The  Paris  basin  is 
from  east  to  west  about  100  miles  in  extent,  and 
180  from  north-east  to  south-west;  the  total  thick- 
ness of  the  beds,  or,  to  use  other  terms,  the  depths 
passed  through  to  reach  the  chalk,  varying  from  one 
to  several  hundred  feet. 

The  strata,  commencing  with  the  lowermost,  or 
most  ancient,  present  the  following  characters : — 

1.  The  lowermost.    Chalk  flints,  broken,  and  par- 
tially rolled,  sometimes   conglomerated  into  ferru- 
ginous  breccia.       A    layer   of   this    kind    is    very 
common  on  the  South  Downs,  immediately  under 
the  turf. 

2.  Plastic  clay,  and  sand.     Clay  and  sand,  with 
fresh-water  shells,  drifted  wood,  lignite,  leaves,  and 


212  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

fruits  ;   intercalated  with  limestone  containing  ma- 
rine shells. 

3.  Silicious  limestone,  fresh-water  and  terrestrial 
shells  and  plants,  and  marine  limestone,  or  Calcaire 
grassier,  a  coarse  compact  limestone,  passing  into 
calcareous  sand,  and  abounding  in  marine  shells. — 
These  beds  often  alternate,  and  are  considered  by 
M.  Constant  Prevost  to  be  contemporaneous  for- 
mations ;    the  marine  strata  having  been  formed  in 
those  parts  of  the  basin  which  were  open  to  the 
sea ;    and   the    fresh-water   limestone,    by  mineral 
waters  poured  into  the  bay  from  the  south ;    the 
continent  being  situated  then,  as  now,  to  the  south, 
and   the   ocean   to  the   north.      Partial    layers   of 
milliolite  limestone,*  almost  entirely  composed  of 
microscopic  chambered  shells,  occur  in  this  part 
of  the  basin. 

4.  Gypseous  marls,  and  limestones,  with  bones  of 
animals,  and  fresh-water  shells  of  fluviatile  origin. 
These  are  supposed  to  have  been  discharged  by  a 
river  which  flowed  into  the  gulf;  the  gypsum  being 
precipitated  from  water  holding  sulphate  of  lime 
in  solution,  in  the  same  manner  as  the  travertine 
or  calcareous  tufa,  of  which  we  have  already  spoken 
(page  56.) 

5.  Upper  marine  formation,  consisting  of  marls, 
micaceous  and  quartzose  sand,  with  beds  of  sand- 
stone abounding  in  marine  shells. 

*  So  called  from  its  inclosing  immense  quantities  of  a  minute 
shell,  named  Milliolite. 


}  18.  THE  LONDON  BASIN.  213 

6.  Upper  fresh-water  marls,  with  interstratified 
layers  of  flint,  containing  seed-vessels  of  aquatic 
plants  (  Charce),  and  animal  and  vegetable  remains. 
These  beds  are  attributed  to  lakes  or  marshes, 
which  existed  after  the  marine  sands  had  filled  up 
the  basin. 

From  this  rapid  sketch,  we  perceive  that  the  strata 
which  occupy  the  Paris  basin,  have  been  produced 
by  a  succession  of  changes  that  readily  admits  of 
explanation  by  the  principles  so  ably  enforced  by 
Hutton,  Playfair,  and  Lyell,  and  explained  in  the 
previous  lecture.  Here  we  have  an  ancient  gulf  of 
the  chalk,  which  was  open  to  the  sea  on  one  side, 
while  on  the  other  it  was  supplied  by  rivers  charged 
with  the  spoils  of  the  country  through  which  they 
flowed,  and  carrying  down  the  remains  of  animals 
and  plants,  with  land  and  river  shells  ;  and  there 
were  occasional  introductions  of  mineral  waters. 
Changes  in  the  relative  level  of  the  land  and  sea 
took  place,  and  thus  admitted  of  new  accumulations 
upon  the  previous  deposits ;  lastly,  the  country  was 
elevated  to  its  present  altitude  above  the  sea.  Muta- 
tions of  this  kind,  as  we  have  already  seen,  are  in 
progress  at  the  present  moment,  and  afford  a  satis- 
factory elucidation  of  these  interesting  phenomena. 
I  reserve  my  remarks  on  the  fossils  of  the  Paris  basin 
to  the  next  section,  and  pass  to  the  examination  of 
the  analogous  beds  in  our  own  island. 

18.  THE  LONDON  BASIN. — The  tertiary  strata 
on  which  the  metropolis  of  England  is  situated  are 


214  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

spread  over  a  considerable  area,  which  is  bounded 
on  the  south  by  the  North  Downs ;   extends  on  the 
west  beyond  High-elm  hill,  in  Berkshire ;   and  on 
the  north-west   is   flanked   by  the   Chalk   hills  of 
Wiltshire,    Berkshire,    Oxfordshire,    Buckingham- 
shire, and  Hertfordshire.     On  the  east  it  is  open  to 
the  sea ;  the  Isle  of  Sheppey,  situated  in  the  mouth 
of  the  Thames,  being  an  outlier  of  the  same  deposit.* 
It  spreads  over  Essex,  a  considerable  part  of  Suf- 
folk,  Epping  and  Hainault  forests,   the  whole  of 
Middlesex,  and  a  portion  of  Bucks.     In  the  imme- 
diate vicinity  of  the  metropolis,  a  stiff  clay  of  a 
bluish-black  colour,  abounding  in  marine  remains, 
constitutes  the  great  mass  of  the  materials  which 
fill  up  this  ancient  gulf  of  the  ocean.     Immediately 
upon  the  chalk,  however,  there  occur  thick  beds  of 
sand  and  clay,  called  Plastic  clay  (from  its  analogy 
to  the  Argile  Plastique  of  the  Paris  basin),  in  which 
fresh-water  shells,  plants,  and  drifted  wood,  have 
been  found  in  some  localities.     In  other  instances, 
layers  of  green  sand  lie  upon  the  chalk,  which  at 
Reading    contain    immense    quantities    of   oyster- 
shells:    a  similar  accumulation  of  shells  has  been 
observed  at  Headley,  in  Surrey,  a  few  miles  from 
Reigate,  by  Mr.  Peter  Martin,  jun.  of  that  town. 
At  Bromley,  in  Kent,  there  is  a  bed  of  oyster-shells 
with  pebbles  of  chalk-flints,  which  are  cemented 
together  by  a  calcareous  deposit  into  a  remarkable 

*  See  Mr.  Webster's  paner  in  the  Geological  Transactions ; 
and  Conybeare  and  Phillips' s  Geology  of  England  and  Wales, 


5  IS.  THE  LONDON  BASIN.  215 

conglomerate,  in  much  request  for  grottoes  and 
ornamental  rock-work.  The  London  clay  is  found 
immediately  beneath  the  gravel  which  so  generally 
forms  the  sub-soil  of  the  metropolis ;  it  is  of  great 
extent,  and  varies  from  300  to  600  feet  in  thickness. 
This  clay  forms  a  dark,  tough  soil,  and  has  occa- 
sional intermixtures  of  green  and  ferruginous  sand, 
and  variegated  clays.  It  abounds  in  spheroidal 
nodules  of  indurated  argillaceous  limestone,  in- 
ternally filled  by  veins  of  calcareous  spar,  or  sul- 
phate of  barytes,  disposed  in  a  radiating  manner 
from  the  centre  of  the  nodule  to  the  circumference. 
From  the  appearance  of  partitions  which  this  cha- 
racter confers,  these  concretions  are  commonly 
known  by  the  name  of  Septaria  :  shells  and  other 
organic  remains  frequently  form  the  nucleus  of 
these  nodules,  which  are  used  in  prodigious  quan- 
tities for  cement.  The  specimens  on  the  table  are 
from  Highgate  and  Bognor ;  two  from  the  latter 
locality,  presented  to  me  by  Dr.  Hall,  contain 
beautiful  examples  of  an  extinct  species  of  nautilus. 
The  septaria  are  commonly  disposed  in  horizontal 
lines,  and  lie  at  unequal  distances  from  each  other. 
Brilliant  sulphuret  of  iron  abounds  in  the  clay, 
and  is  sjeen  in  this  septarium,  as  well  as  in  many  of 
the  organic  remains.  Crystallized  sulphate  of  lime, 
or  selenite,  is  also  common  in  these  as  in  other  ar- 
gillaceous strata.  The  cuttings  through  Highgate 
Hill,  to  form  the  archway  ;  the  excavations  in  the 
Jlegent's  Park;  and  more  recently  the  tunnels 


216  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

carried  through  a  part  of  the  same  ridge  of  clay 
at  Primrose  Hill,  in  the  line  of  the  Birmingham 
railroad ;  and  the  explorations,  by  wells,  over  the 
whole  area  around  London,  have  brought  to  light 
such  prodigious  quantities  of  organic  remains,  that 
the  fossils  of  this  deposit  are  almost  universally 
known.  The  admirable  work  of  the  late  Mr. 
Sowerby,  called  early  attention  to  these  testaceous 
remains,  the  first  plate  in  his  Mineral  Conchology 
being  devoted  to  the  "  Nautili  of  the  London  Basin." 
Immense  numbers  of  marine  shells  of  extinct  spe- 
cies ;  crabs,  lobsters,  and  other  Crustacea ;  teeth 
of  sharks,  and  remains  of  many  genera  of  fishes ; 
bones  of  crocodiles  and  turtles;  leaves,  fruits,  stems 
of  plants,  and  rolled  trunks  of  trees,  perforated  by 
boring  shells, — occur  throughout  these  strata,  but 
are  located  in  greater  abundance  in  some  spots  than 
in  others.  The  clay  and  gravel  pits  at  Woolwich, 
on  the  banks  of  the  Thames,  abound  in  univalve 
shells ;  and  at  Plumstead,  Bexley,  and  other  places, 
marine  bivalve  shells  occur  in  clay,  and  in  indurated 
argillaceous  limestone. 

19.  THE  ISLE  OF  SHEFPEY. — The  Isle  of  Sheppey 
is  entirely  composed  of  the  London  clay,  and  the 
thickness  of  the  beds  is  upwards  of  550  feet.  It  has 
long  been  celebrated  for  its  organic  remains ;  and 
I  may  observe,  that  the  discovery  of  seed-vessels 
and  stems  of  plants  in  pyritous  clay,  in  a  visit  which 
I  made  to  Queenborough,  when  a  youth,  tended  to 
confirm  my  early  taste  for  geological  researches. 


§  20.         FOSSIL  FRUITS  OF  THE  TERTIARY  STRATA.        217 

The  cliffs  on  the  north  of  the  island  are  about 
200  feet  high,  and  consist  of  clay,  abounding  in 
septaria,  which  are  washed  out  of  the  cliffs  by  the 
action  of  the  sea,  and  are  collected  for  cement. 
The  organic  remains  are,  however,  unfortunately 
so  strongly  impregnated  with  pyrites,  that  the  col- 
lector often  finds  the  choicest  fossil  fruits  in  his 
cabinet,  like  the  fabled  apples  of  the  Dead  Sea,  one 
moment  perfect  and  brilliant,  and  the  next  decom- 
posed and  changed  to  dust,  leaving  only  an  efflo- 
rescent sulphate  of  iron.  The  same  species  of 
animal  and  vegetable  remains  that  are  found  in 
the  blue  clay  of  the  metropolis,  abound  in  profusion 
in  the  Isle  of  Sheppey. 

20.    FOSSIL  FRUITS  OF  THE  TERTIARY  STRATA. 

— Seed-vessels,  and  stems  and  branches  of  trees,  of  a 
tropical  character,  probably  drifted  by  currents  into 
the  gulf  of  the  London  basin,  occur  in  such  abun- 
dance and  variety,  that  the  existence  of  a  group  of 
spice  islands  seems  necessary  to  account  for  so  vast 
an  accumulation  of  vegetable  productions.  The 
seed-vessels  found  at  Sheppey  are  referable  to 
several  hundred  species  ;  some  are  related  to  the 
cardamom,  date,  areca,  cocoa;  and  one  species  of 
berry  bears  much  resemblance  to  the  fruit  of  the 
coffee.  The  wood  found  in  the  Sheppey  clay  is 
generally  of  a  dark  colour,  with  the  ligneous  fibres 
and  circles  of  growth  well  developed ;  it  is  often 
veined  with  brilliant  pyrites,  and  the  fissures  and 
cavities  are  frequently  filled  with  that  mineral.  It 


218  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

is  rarely  that  any  considerable  mass  of  wood  is 
found  free  from  the  ravages  of  a  species  of  teredo, 
resembling  the  recent  teredo  navalis,  or  borer,  which 
inhabits  the  seas  of  the  West  India  islands.  The 
tubular  shells  sometimes  remain,  but  their  cavities, 
as  well  as  the  perforations  in  the  wood,  are  filled 
with  pyrites,  indurated  clay,  argillaceous  limestone, 
or  calcareous  spar ;  and  specimens,  when  cut  and 
polished,  exhibit  interesting  sections  of  the  mean- 
dering grooves  of  the  teredines.  In  this  specimen, 
from  the  banks  of  the  canal  in  the  Regent's  Park, 
the  grain  of  the  wood,  with  the  shells,  and  their 
excavations,  are  beautifully  displayed. 

21.  UPPER  MARINE,  or  BAGSHOT  SAND. — At 
Highgate  and  Hampstead,  Purbright  and  Frimley 
Heaths,  in  Surrey,  and  on  Bagshot  Heath,  extensive 
beds  of  sand  occur,  with  but  few  traces  of  organic 
remains ;  those  hitherto  observed  are  principally 
x;asts  of  marine  shells.  In  cutting  through  the 
summit  of  Goldworth  hill,  four  miles  north  of  Guild- 
ford,  on  the  line  of  the  London  and  Southampton 
railway,  teeth  and  other  remains  of  several  genera 
of  fishes  have  lately  been  discovered  ;  the  teeth  of 
sharks,  and  the  palates  of  rays,  are  the  most  nume- 
rous. One  large  tooth  of  a  saw-fish,  affords  the 
first  well-authenticated  example  of  the  genus  pris- 
tris,  in  a  fossil  state,  in  England  ;  and  there  have 
also  been  found  teeth  of  several  new  genera  of 
cartilaginous  fishes^  related  to  psammodus.*  The 
.  *  Proceedings  of  the  Geological  Society,  vol.  ii.  p.  687. 


122.  ARTESIAN  WELLS.  219 

boulders  and  masses  of  sandstone,  which  are  abun- 
dant in  some  of  the  chalk  valleys  and  on  the  flanks 
of  the  Downs,  are  called  Sarsden- stone,  or  Druid 
sandstone,  from  being  the  principal  material  em- 
ployed in  the  construction  of  Stonehenge,  and  other 
Druidical  monuments  ;  they  are  supposed  to  have 
been  derived  from  the  sand-beds,  which  overlie  the 
London  clay  in  the  places  above  named ;  they  may, 
however,  have  belonged  to  the  sands  which  lie  be- 
tween the  clay  and  chalk.  The  wastes  and  unpro- 
ductive heaths  around  the  metropolis,  are  sites  of 
these  arenaceous  deposits,  which  also  form  the  sub- 
soil of  that  charming  and  picturesque  spot,  Hamp- 
stead  Heath.  The  gravel  and  shingle,  associated 
with  the  sands,  have  unquestionably  been  derived 
from  the  ruins  of  the  chalk  formation. 

22.  ARTESIAN  WELLS. — As  from  the  alternation 
of  porous,  arenaceous  strata,  with  stiff  or  impervious 
JDeds  of  clay,  the  artificial  perennial  fountains,  called 
Artesian  wells,  are  of  frequent  occurrence  in  the 
vicinity  of  the  metropolis,  I  will  in  this  place  offer 
a  few  remarks  on  the  phenomena  of  springs.  The 
descent  of  moisture  from  the  atmosphere  upon 
j;he  earth,  and  its  escape  into  the  basin  of  the 
ocean,  by  the  agency  of  streams  and  rivers,  were 
noticed  in  the  first  lecture.  The  rain  falling  on  a 
gravelly  or  porous  soil,  will,  of  course,  descend 
through  it,  till  its  progress  is  arrested  by  a  clayey  or 
impervious  stratum,  which  will  thus  form  a  natural 
tank  or  reservoir,  collect  the  water,  and  a  subter- 


220  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

ranean  pool  or  canal  will  be  the  result,  according 
to  the  direction  and  configuration  of  the  upper 
surface  of  the  clay.  This  state  of  things  will  con- 
tinue, till,  by  an  increased  supply,  the  water  rises 
above  the  level  of  the  basin,  or  channel,  and  over- 
flowing, escapes,  either  through  the  porous  strata, 
or  by  fissures  in  the  solid  rocks,  to  another  level. 
If  the  course  of  the  waters  be  subterranean,  the 
softer  beds  are  worn  away,  and  chasms  or  caverns 
are  thus  formed,  hence  rivers  and  streams,  of  great 
extent,  occur  in  many  of  our  mines  ;  but  if  the  water 
finds  its  way  to  the  surface,  a  spring  bursts  forth. 
This  is  the  nature  of  all  springs,  except  those  wrhich 
arise  from  great  depths,  and  probably  originate 
from  the  condensation  of  steam,  evolved  through 
fissures  by  volcanic  agency  j  such  are  the  thermal 
waters  of  many  countries.  Streams  impregnated 
with  the  mineral  substances  contained  in  the  strata 
through  which  they  flow,  are  called  mineral  waters. 
Those  in  the  tertiary  strata  near  Epsom,  contain 
sulphate  of  magnesia,  whence  the  name  of  Epsom 
salt,  given  to  this  substance  wherever  it  occurs. 
But  strata  which  are  pervious,  frequently  alternate 
with  others  which  are  not  so  ;  or  may  form  a  basin, 
the  area  of  which  is  partially  filled  with  clay,  through 
which  water  cannot  pass  :  in  such  a  case,  it  is  ob- 
vious that  the  bed  of  sand  beneath  the  clay,  fed  by 
the  rain  which  descends  on  the  uncovered  margin 
of  the  basin,  must  form  a  reservoir,  and  the  water 
gradually  accumulate  beneath  the  central  plateau 


§  22.  ARTESIAN  WELLS.  221 

of  clay,  through  which  it  cannot  escape.  If  this 
bed  of  clay  be  penetrated,  either  by  natural  or  arti- 
ficial means,  the  water  must  necessarily  rise  to  the 
surface,  and  may  be  even  thrown  up  in  a  jet  to  an 
altitude  which  will  depend  on  the  level  of  the  fluid 
in  the  subterranean  reservoir  ;  such  is  the  pheno- 
menon observable  in  the  Artesian  wells  around 
London.  Argillaceous  strata  are  generally  found 
to  be  dry  within  ;  and  the  blue  clay  confines  the 
water  contained  in  the  sands  beneath ;  the  engineer 
perforates  the  clay,  introduces  tubes,  and  taps  the 
natural  tank ;  by  this  method,  the  perennial  foun- 
tains of  Tooting,  Hammersmith,  Fulham,  &c.  have 
been  obtained.*  The  wells  sunk  into  the  London 

3  LONDON. 


a  b     d          c      b  d    c 

TAB.  35. — PLAN  OF  THE  ARTESIAN  WELLS  NEAR  LONDON. 
1.    The  London  clay.     2.   Plastic  clay  and  sand.     3.   The  chalk. 

clay  (Tab.  35,  1,  d,  d,)  yield  no  water;  but  the 
sandy  strata  alternating  with  the  clays,  afford  a 
supply,  the  quantity  and  quality  of  which  depend  on 
the  nature  of  the  rock.  The  borings,  which  reach 

*  Consult  Dr.  Buckland's  Bridgewater  Essay,  p.  561  ;  and 
an  admirable  Essay  on  Artesian  Wells,  in  that  excellent  scien- 
tific periodical,  the  Mining  Journal,  conducted  by  H.  English, 
Esq.,  F.G.S. 


222  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

the  sands  of  the  plastic  clay  (Tab.  35,  2,  c,  ct)  fur- 
nish good  soft-water ;  and  the  wells  that  extend 
to  the  chalk  (Tab.  35,  3,  a,  b,  b,)  afford  an  abun- 
dant supply,  which  often  rises  to  the  surface  in 
a  perennial  fountain,  for  the  chalk  rests  on  an  im- 
pervious bed  of  marl  and  clay.  Of  the  practical 
utility  of  geological  knowledge,  even  in  the  common 
operation  of  sinking  a  well,  I  once  had  a  striking 
proof.  A  gentleman  residing  in  Sussex,  on  the 
borders  of  the  Forest  Ridge,  who  had  seen  with 
admiration  the  perpetual  springs  in  the  environs  of 
the  metropolis,  determined  to  form  one  in  his  grounds 

at Park.      Accordingly,   a  person   conversant 

with  the  construction  of  the  Artesian  wells  around 
London  was  employed,  and  the  necessary  apparatus 
obtained  :  but  the  engineer,  being  wholly  ignorant 
of  the  nature  of  the  strata,  carried  his  operations  to 
a  great  depth,  through  the  beds  of  the  wealden 
sand  of  which  the  district  is  composed,  and,  of 
course,  without  success,  as  the  least  geological 
knowledge  of  the  strata  of  the  country  would  have 
foretold.  The  undertaking,  after  considerable 
labour  and  expense,  was  abandoned. 

23.  THE  HAMPSHIRE,  OR  ISLE  OF  WIGHT  BASIN. 
— The  London  basin  presents  but  little  analogy  to 
the  alternate  marine  and  freshwater  deposits  of  that 
of  Paris ;  but  in  Hampshire  and  the  Isle  of  Wight, 
there  is  an  extensive  suite  of  tertiary  strata,  com- 
posed of  clays,  sands,  and  limestones,  containing 
freshwater,  with  intercalations  of  marine  remains. 


§  24.  ALUM  BAY.  22,'J 

This  group  extends  over  a  considerable  district. 
On  the  east,  a  small  outlier  of  the  lower  beds 
appears  at  Castle  Hill,  near  Newhaven,  in  Sussex  ;* 
but  to  the  westward  of  Brighton,  beyond  Wor- 
thing, the  London  clay  rises  to  the  surface,  and 
forms  the  sub-soil  between  the  Downs  and  the 
sea-shore.  The  inland  boundary  stretches  by  Chi- 
chester,  Emsworth,  and  Southampton,  to  Dorches- 
ter ;  and  the  clay  is  spread  over  the  whole  area  of 
the  New  Forest  and  the  Trough  of  Poole,  being 
flanked  by  the  chalk  on  the  north,  north-east,  and 
north-west,  and  open  to  the  sea  on  the  south.  The 
Isle  of  Wight,  although  now  separated  from  the 
main  land,  is  a  disrupted  mass  of  the  formations  of 
the  south-east  of  England ;  the  chalk  basin  having 
been  broken  up,  and  the  chalk  and  the  superim- 
posed sands,  clays,  and  gravel,  in  some  instances, 
thrown  into  a  vertical  position.  A  remarkable  and 
well-known  instance  of  this  phenomenon  occurs  at 
Alum  Bay,  so  called  from  the  alum,  formerly  ex- 
tracted from  the  decomposing  pyrites,  with  which 
the  clay  abounds. 

24.  ALUM  BAY. — This  sketch  (Tab.  36)  conveys 
a  general  outline  of  the  bay  ;  o,  represents  the  ver- 
tical chalk ;  b,  b,  the  corresponding  tertiary  strata, 
consisting  of  sands  and  clays  of  an  infinite  variety  of 
colour,  and  containing  abundance  of  shells.  Advan- 
tage is  taken  of  the  diversified  tints  of  the  sands  to 
represent,  in  glass  vessels,  landscapes  of  the  island, 
*  Geology  of  the  South-East  of  England,  p.  53. 


221 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


which  are  sold  to  visitors.  The  appearance  of  Alum 
Bay  is  thus  graphically  described  by  Mr.  Webster, 
whose  able  memoir  on  the  strata  above  the  English 
chalk,  formed  a  new  era  in  British  Geology,  and 
raised  our  tertiary  series  to  an  importance  equal  to 


TAB.  36.— ALUM  BAY,  ISLE  OF  WIGHT. 
a,  vertical  strata  of  chalk,     b,  b,  vertical  tertiary  strata. 

that  of  the  Paris  basin.  "  The  clays  and  sands  of 
Alum  Bay  afford  one  of  the  most  interesting  natural 
sections  imaginable.  They  exhibit  the  actual  state  of 
the  strata  immediately  above  the  chalk,  before  anv 
change  took  place  in  the  position  of  the  latter.  For, 
although  the  beds  of  which  they  are  composed  are 
quite  vertical,  yet  from  the  nature  and  variety  of 
their  composition,  and  the  regularity  and  number  of 
their  alternations,  no  one  who  views  them  can  doubt 


«  25.         LONDON  CLAY  OF  THE  HAMPSHIRE  BASIN.         22"> 

that  they  have  suffered  no  change,  except  that  of 
having  been  moved  with  the  chalk  from  a  horizontal 
to  a  vertical  position.  These  sands  and  clays  pre- 
sent every  variety  of  colour  of  green,  yellow,  red, 
crimson,  ferruginous,  white,  black,  and  brown." 
Beds  of  pipe-clay  also  occur ;  some  of  which  con- 
tain layers  of  wood-coal,  with  branches  and  leaves. 
The  coal  burns  with  difficulty,  and  emits  a  strong 
sulphureous  smell ;  masses  are  constantly  drifted 
by  the  sea  and  thrown  on  the  shore  near  Brighton, 
where  this  substance  was  formerly  used  as  fuel  by 
the  poorer  inhabitants.* 

25.  LONDON  CLAY  OF  THE  HAMPSHIRE  BASIN. 
— The  London  clay  extends  over  the  greater  portion 
of  the  area  of  the  Hampshire  basin,  its  peculiar 
fossils  abounding  in  many  localities.  Castle  Hill, 
near  Newhaven,  which  has  been  already  mentioned, 
is  a  series  of  sands,  marls,  and  clays,  with  beds  of 
oyster-shells  and  of  shingle  that  occupy  the  upper 
part  of  the  hill,  and  rest  upon  the  chalk  which  forms 
the  lowermost  fifty  feet  of  the  cliff.  The  sub- 
sulphate  of  alumine,-^  a  mineral  substance  peculiar 

this  locality,  occurs  in  the  ochraceous  clay  which 
is  in  immediate  contact  with  the  chalk.  Selenite, 
or  crystallized  gypsum,  abounds  in  the  gypseous 
marls;  a  layer  of  surturbrand,  or  wood-coal,  a 
few  inches  thick,  contains  impressions  of  land- 

*  See  Geology  of  the  South  Downs,  p.  261. 
t  British  Mineralogy,  Tab.  499.      Geology  of  the  South- 
East  of  England,  p.  56. 

Q 


226  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

plants  ;*  and  the  argillaceous  beds  contain  marine 
and  fresh-water  shells  in  such  abundance,  that  some 
of  them  are  mere  masses  of  compressed  shells,  held 
together  by  argillaceous  earth.  The  oysters  are  con- 
solidated into  coarse  stone,  and  where  pebbles  enter 
into  the  composition  of  this  concrete,  a  close  resem- 
blance is  presented  to  the  Bromley  oyster  conglo- 
merate (p.  214).  Teeth  of  sharks  have  been  collected 
in  these  strata.  At  Chimting  Castle,  near  Seaford, 
on  the  eastern  escarpment  of  the  valley  of  the  Ouse, 
olive-green  sand,  and  a  ferruginous  conglomerate 
of  chalk-flints,  lie  upon  the  chalk,  thus  determining 
the  original  extension  of  the  tertiary  beds  along 
the  Sussex  coast.-)-  Westward  from  Brighton,  the 
London  clay  is  perceived  near  Worthing,  emerging 
from  beneath  those  newer  deposits  which,  as  we 
have  already  seen,  contain  remains  of  elephants. 
At  Bognor,  an  arenaceous  limestone,  full  of  the 
usual  shells  of  the  Calcaire  grassier  and  London 
clay,J  constitutes  a  group  of  low  rocks,  which  in 
another  century  will  probably  have  entirely  dis- 
appeared. The  beauty  and  variety  of  the  shells, 
particularly  of  the  nautili,  and  of  the  perforated 
fossil  wood,  render  these  organic  remains  objects 
of  great  attraction.  In  the  blue  clay  at  Bracklesham 
Bay,  and  at  Stubbington,  on  the  western  coast  of 
Sussex,  fossil  shells  may  be  obtained  at  low- water 

*  Fossils  of  the  South  Downs,  PI.  viii.  figs.  1, 2, 3, 4. 
f  Geology  of  the  South-East  of  England,  p.  62. 
J  Fossils  of  the  South  Downs,  p.  271. 


}  26.     FRESH- WATER  STRATA  OF  THE  ISLE  OF  WIGHT.      227 

in  profusion;  and  Hordwell  Cliff,  in  Hampshire, 
has  so  long  been  celebrated  for  similar  productions, 
that  its  elegant  shells  are  seen  in  almost  every  col- 
lection of  organic  remains.  In  all  these  localities 
the  shells  are  of  the  same  genera  and  species  with 
those  of  the  contemporaneous  deposits  of  France. 

26.  FRESH-WATER  STRATA  OF  THE  ISLE  OF 
WIGHT. — The  great  peculiarity  and  interest  of  the 
Isle  of  Wight  basin,  as  compared  with  that  of 
London,  consists  in  the  existence  of  strata  con- 
taining almost  exclusively  fresh-water  shells  and 
remains  of  the  same  kind  of  animals  as  those  which 
occur  in  the  vicinity  of  Paris.  Mr. Webster  arranged 
the  tertiary  beds  of  Hampshire,  in  the  following 
manner: — 1st.  Lowermost;  Plastic  clay  and  sand. 
2d.  London  clay.  3d.  Fresh- water  deposits, — 
sandy  calcareous  marls,  with  immense  quantities  of 
fresh- water  shells.  4th.  Clay  and  marl,  abounding 
in  marine  shells  ;  very  generally  of  different  species 
from  those  of  the  London  clay.  5th.  Upper  fresh- 
water deposit;  yellowish  white  marl,  and  calcareous 
limestone,  employed  for  building  ;  nearly  sixty  feet 
in  thickness,  and  almost  one  entire  mass  of  fresh- 
water shells. 

Subsequent  observations  have  shown  that  the 
above  subdivisions  have  been  made  from  too  partial 
a  view  of  the  phenomena,  and  that  the  entire  suite 
of  deposits  must  be  regarded  as  a  fresh-water  for- 
mation, into  which  there  have  been  occasional 
irruptions  of  the  sea. 

Q2 


228  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

The  above  series  is  well  developed  at  Headon 
Hill,  where  the  fresh-water  strata,  which  succeed 
those  of  Alum  Bay,  lie  in  a  nearly  horizontal 

Headon  Hill.  Alum  Bay. 


1  2 

TAB.  37.— SECTION  OF  HEADON  HILL  AND  ALUM  BAT. 

Fig.  1.    The  horizontal  fresh-water  beds  of  Headon  Hill.     2.  Vertical 
tertiary  strata  of  Alum  Bay.    3.  Almost  vertical  beds  of  chalk. 

direction.  At  Binstead,  near  Calbourne,  and 
Morley,  quarries  have  been  opened  in  the  fresh- 
water limestone  ;  and  bones  and  teeth  of  Anoplo- 
therict,  Palceotheria,  of  the  Chiropotamus  an  animal 
allied  to  the  Peccari,  and  of  a  species  of  Moschus, 
have  been  discovered. 

27.  ORGANIC  REMAINS  OF  THE  PARIS,  LONDON, 
AND  HANTS  BASINS. — So  numerous  are  the  relics 
of  the  inhabitants  of  the  ancient  land  and  water 
entombed  in  the  strata  which  we  have  thus  cur- 
sorily surveyed,  that  I  can  only  attempt  a  brief 
description  of  the  organic  remains.  To  condense 
my  remarks  as  much  as  possible,  I  shall  select  the 
fossils  of  the  Paris  basin  as  the  types  of  the  zoology 
of  the  older  tertiary  epoch,  and  include  notices  of 
such  species  as,  occurring  in  British  and  other 
localities,  may  be  requisite  for  the  illustration  of 
the  subject. 


§  28.                  FOSSIL  PLANTS  AND  ZOOPHYTES.  221) 

28.     FOSSIL    PLANTS    AND    ZOOPHYTES. Fossil 

wood  occurs  in  vast  abundance,  particularly  in  the 
state  of  large  trunks  and  branches,  which  appear 
to  have  been  drifted,  and  are  full  of  perforations 
inclosing  shells  of  boring  mollusca.  Bognor  rocks, 
the  clay  around  London,  of  the  Isle  of  Sheppey,  £c. 
abound  in  specimens  of  this  kind.  The  wood  is 
dicotyledonous,  that  is,  like  the  oak,  ash,  &c. ;  its 
mode  of  increase  was  by  annular  circles  of  growth, 
as  will  be  explained  in  the  lecture  on  Fossil  Botany. 
Leaves  and  stems  of  palms  have  been  found  in  the 
Paris  basin,  and  in  the  Isle  of  Sheppey,  &c.;  and  a 
trunk  of  a  tree  related  to  the  palm,  nearly  four  feet 
in  diameter,  at  Soissons.  Fruits  belonging  to  trees 
allied  to  the  areca,  pine,  fir,  cocoa-tree,  &c.  have 
been  discovered  in  several  localities.  Accumula- 
tions of  vegetable  matter,  in  the  state  of  lignite  or 
brown  coal,  occur  at  Bovey  Tracey  in  Devonshire, 
and  in  various  parts  of  France,  the  Netherlands,  &c. 
Amber,  and  a  substance  which  has  been  called 
Highgate  resin,  are  occasionally  imbedded  in  these 
deposits. 

ZOOPHYTES.  —  Polyparia,  or  corals,  occur  in 
some  of  the  marine  strata,  but  they  are  not  very 
numerous  ;  several  species  of  turbinolia,  caryo- 
phyllia,  fungia,  and  other  corals,  are  figured  and 
described  by  authors.  I  have  a  few  specimens 
from  Grignon.  The  modern  tertiary  (those  of 
Palermo)  abound  in  various  kinds  of  flustra  and 
spongia. 


230  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

29.  MARINE  AND  FRESH-WATER  SHELLS  OF 
THE  TERTIARY  STRATA. —  So  numerous  are  the 
shells  of  the  tertiary  epoch,  already  determined  by 
naturalists,  that  they  exceed  one-half  of  the  known 
living  species,  amounting  to  nearly  three  thousand. 
We  have  already  seen  that  some  of  the  strata  are 
almost  entirely  composed  of  these  remains  in  a 
broken  and  compressed  state  :  at  Newhaven,  in 
Sussex,  many  seams  in  the  argillaceous  beds  wholly 
consist  of  shell-dust.  In  other  localities  the  shells 
occur  in  the  most  perfect  state;  and  Grignon,  a 
few  leagues  from  Paris,  has  long  been  celebrated 
for  its  beautiful  fossils,  hundreds  of  species  of 
shells  peculiar  to  the  older  tertiary  strata  having 
been  collected  in  one  spot  alone :  these  belong  to 
the  Calcaire  grassier,  and  many  of  the  species  occur 
in  the  London  and  Hampshire  basins,  and  Bognor 
rocks.  I  have  selected  a  few  specimens,  from  those 
in  my  possession,  to  convey  an  idea  of  their  usual 
characters  and  appearance.  (Tab.  38.) 

Although,  in  mentioning  the  names  of  these 
shells,  I  do  not  expect  that  any  but  the  scientific 
inquirer  will  endeavour  to  fix  them  on  the  memory, 
yet  it  is  useful  to  point  out  to  you  the  characters 
which  prevail  in  these  tertiary  beds  ;  for,  as  I  have 
already  stated,  certain  fossils  are  peculiar  to  certain 
strata,  and  the  experienced  geologist  can  often,  at  a 
glance,  determine  the  relative  antiquity  of  a  deposit 
by  an  examination  of  a  few  species  of  shells.  The 
whole  of  these  forms  must  be  familiar  to  you, 


§29. 


SHELLS  OF  THE  TERTIARY  STRATA. 


231 


because  they  belong  to  genera  which  have  species 
still  living  in  our  present  seas.  The  Cyprtea,  or 
cowry  (tig.  1),  and  the  Anci/la,  or  olive,  (fig.  2), 


TAB.  38. — MARINE  SHELLS  OF  THE  PARIS  BASIN. 

?.  1.  Cyprsea  inflata.  2.  Ancilla  canalifera.  3.  Fusus  uniplicatus. 
4.  Cerithium  laraellosum.  5.  Pleurotoma  dentata.  6.  Lucina  sulcata. 
7.  Ampullaria  sigaretina.  8.  Pectunculus  angusti-costatus. 

are  well-known  types.  The  Cerithium  (fig.  4) 
belongs  to  a  genus  which  is  most  abundant  in  the 
sands  of  the  Paris  basin,  and  is  remarkable  for  the 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


elegance,  number,  and  variety  of  the  species,  which 
exceed  by  three  times  those  of  their  living  ana- 
logues. The  Cerithium  giganteum  attains  a  con- 
siderable magnitude.  Some  masses  of  the  Bognor 
rock  are  almost  wholly  composed  of  a  species  of 
Pectunculus.  The  Ampullaria  (Tab.  38,  fig.  7) 
abounds  at  Grignon,  and  is  commonly  in  a  beau- 
tiful state  of  freshness.  You  will  recollect  that  in 
most  of  the  carnivorous  species  the  aperture  of  the 
shell  is  channelled.  (Tab.  38,  figs.  2,  3,  4,  5.) 
1  2 


TAB.  39. — FRESH-WATER  SHELLS  OF  THE  PARIS  BASIN. 

Figs.  1,  2.  Bulimus  conicus.    3,4.  Cyclostoraa  mumia.     5.  Lymnea 

effilea.    6,  7,  8.  Planorbis. 

FRESH-WATER  TERTIARY  SHELLS. — It  has  al- 
ready been  observed,  that  the  shells  of  the  mollusca 


§  30.  NUMMUL1TES.  233 

which  inhabit  fresh  water,  possess  characters  by 
which  they  may  be  distinguished  from  the  marine 
species.  This  small  selection  from  the  fresh-water 
beds  of  Paris  will  serve  to  elucidate  my  observa- 
tions. The  general  appearance  of  these  shells  will 
bring  to  your  recollection  the  species  which  inhabit 
our  ponds  and  rivers ;  particularly  the  large  thiu 
snail  (lymnea,  fig.  5)  and  the  discoidal  shells  {plan- 
orbis,  figs.  6,  7,  8) ;  while  figs.  3  and  4>  (cyclostoma) 
resemble  a  species  often  found  on  the  banks  of 
lakes.  At  Headon  Hill,  and  at  Binstead  in  the 
Isle  of  Wight,  the  clay  and  limestone  are  filled 
with  the  remains  of  several  species  of  planorbis 
and  lymnea. 

30.    NUMMULITES,    AND    OTHER   CEPHALOPODA. 

— Several  species  of  nautilus  abound  in  the  tertiary 
strata ;  those  inclosed  in  the  septaria,  or  indurated 
argillaceous  nodules,  of  the  London  clay  at  High- 
gate,  Sheppey,  and  Bognor,  possess  considerable 
beauty,  and  admit  of  being  cut  in  sections,  which 
admirably  display  the  internal  structure  of  the 
original.  I  shall,  however,  defer  an  explanation  of 
their  mechanism  to  the  subsequent  lecture,  when 
analogous  fossil  genera  will  come  under  our  notice. 
My  observations  will  now  be  restricted  to  an  in- 
teresting division  of  the  Cephalopoda  (as  those 
mollusca  are  termed  whose  head  is  surrounded  by 
the  organs  of  motion,  or  feet),  called  Foraminifera, 
which  comprehends  many  genera,  and  several  hun- 
dred species,  the  greater  part  being  microscopic, 


234 


THE  WONDERS  OF  GEOLOGY. 


LECT.III. 


and  analogous  to  the  recent  forms  which  inhabit 
the  Mediterranean.  These  bodies  are  entirely 
distinct  from  the  testaceous  habitations  of  snails, 
periwinkles,  &c. :  they  are,  in  truth,  not  an  ex- 
ternal, but  an  internal  apparatus;  and  it  is  sup- 
posed, that,  in  addition  to  their  having  served  as 
a  point  of  attachment  and  support  to  the  soft 
body  of  the  animal,  they  acted  as  a  buoy,  which 
could  be  made  heavier  or  lighter  at  pleasure,  and 
by  which  the  animal  was  enabled  either  to  sink 


TAB.  40.— NUMMULITES,  FROM  THE  GREAT  PYRAMID  OF  EGYPT. 
(Collected  by  Dr.  George  Hall,  of  Brighton.) 

Fig.  1.  Transverse  section  of  a  Nummulite.    2,  3.  Nummulites,  with  the 
external  plate  partially  removed. 

or  swim.     The  fossil  called  Nummulite  (from  its 
resemblance  to  a   coin)  affords  a  beautiful  illus- 


§  30.  NUMMULITES  OF  THE  PYRAMIDS.  235 

tration  of  the  structure  of  these  bodies.  It  is 
of  a  lenticular,  discoidal  form,  and  varies  in  size 
from  a  mere  point  to  an  inch  and  a  half  in  diameter. 
The  outer  surface  is  generally  smooth,  and  marked 
with  fine  undulating  lines-  On  splitting  the  shell 
transversely,  it  is  found  to  consist  of  several  coils, 
which  are  divided  into  a  great  many  cells  or  cham- 
bers by  oblique  partitions  (Tab.  40,  fig.  1),  appa- 
rently having  no  communication  with  each  other, 
but  which  the  animal,  probably,  had  the  power  of 
filling  with  fluid,  or  air,  through  foramina  or  pores  ; 
whence  the  name  of  the  order.  To  Dr.  George 
Hall  (physician  to  the  Sussex  Hospital),  I  am  in- 
debted for  the  specimens  exhibiting  this  structure, 
which  I  now  place  before  you  (Tab*  40) ;  they  are 
from  the  limestone  formed  of  nummulites,  held 
together  by  calcareous  cement,  which  constitutes 
the  foundation  rock  of  the  Great  Pyramid  of  Egypt, 
and  of  which  that  structure  is  in  part  composed. 
Strabo  alludes  to  the  nummulites  of  the  pyramids, 
under  the  supposition  that  they  are  lentils  which 
had  been  scattered  about  by  the  workmen,  and 
become  converted  into  stone.*  This  polished,  sili- 
cious  pebble,  presented  me  by  the  Marquess  of 
Northampton,  is  also  from  Egypt;  the  markings 
on  the  surface  are  sections  of  the  inclosed  shells. 
The  uummulite  is  one  of  the  most  widely  diffused 
of  fossil  shells,  its  remains  forming  whole  chains  of 

*  See  Wilkinson's  Manners  and  Customs  of  the  Ancient 
Egyptians,  vol.  ii.  p.  371. 


236  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

calcareous  hills :  it  is  not  confined  to  the  tertiary, 
but  occurs  also  in  the  secondary  formations,  and 
constitutes  immense  beds  in  the  Alps  and  Pyrenees. 
The  blue  clay  at  Bracklesham  and  at  Stubbington, 
and  the  calcareous  sandstone  of  Emsworth  and 
Bognor,  in  Sussex,  abound  in  nummulites.  In 
North  America,  the  limestone  which  occurs  near 
Suggsville,  and  forms  a  range  of  hills  about  300 
feet  in  height,  is  entirely  composed  of  one  species 
of  nummulite.  This  limestone  is  porous,  and  con- 
tains  spheroidal  cavities  formed  by  the  decompo- 
sition of  the  organic  remains.* 

31.  CRUSTACEA  AND  FISHES. — Crabs  and  lob- 
sters, of  species  related  to  the  recent,  several  of 
which  are  described  by  MM.  Brongniart  and  Des- 
marest,  in  their  beautiful  work  on  Fossil  Crustacea, 
have  been  found  in  the  clay  of  Highgate,  and  in 
the  Isle  of  Sheppey.  The  external  configuration  of 
the  shell  or  crustaceous  covering  of  these  animals 
being  in  conformity  to  the  viscera  which  they  in- 
close and  are  intended  to  protect,  the  naturalist  is 
able,  by  au  accurate  acquaintance  with  the  charac- 
ters of  the  living  species,  to  point  out  the  relation 
or  difference  of  the  fossil,  even  though  the  cara- 
pace or  buckler  alone  remains  ;  and  the  size  and 
situation  of  the  heart,  stomach,  &c.  may  thus  be 
readily  determined.  This  remarkably  fine  crab 

*  Nummulites  Mantellii  of  Dr.  Morton.  See  Synopsis  of  the 
Organic  Remains  of  the  Cretaceous  Group  of  North  America. 
8vo,  with  numerous  plates.  Philadelphia. 


§  32.  FOSSIL  CRAB.                                         237 

(Tab.  41)  is  from   Malta;    it  shows  the  state  of 

perfection   in  which  fossil  Crustacea  are  sometimes 
discovered. 


TAB.  41. — FOSSIL  CRAB,  FROM  MALTA.* 
(Cancer  Macrochelus.) 

Seven  or  eight  species  of  fishes,  of  extinct  genera, 
have  been  found  in  the  Paris  basin  alone.  The 
teeth  of  several  kinds  of  sharks  (lamnd)  occur  everv 
where,  and  are  known  by  the  name  of  "  birds'  bills." 
In  the  clay  of  Sheppey  and  London,  beautiful  fossil 
fishes  have  been  found,  the  scales  possessing  a 
metallic  lustre,  from  an  impregnation  of  sulphuret 
of  iron.  But  I  must  pass  cursorily  over  these  re- 
mains, as  well  as  those  of  crocodiles,  turtles,  and 
tortoises,  which  are  imbedded  in  these  deposits. 

32.  FOSSIL  BIRDS. — In  the  gypseous  building- 
stone  of  Montmartre,  M.  Cuvier  found  many  bones 
which  possessed  characters  peculiar  to  those  of 
*  One  half  the  size  of  the  original. 


238 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


birds ;  and  after  much  research  he  was  enabled  to 
determine  several  fossil  species,  related  to  the  peli- 
can, sea-lark,  curlew,  woodcock,  buzzard,  owl,  and 
quail.  In  some  examples  there  are  indications  of 
the  feathers,  and  even  of  the  air-tubes.  Sometimes 
the  skeleton  is  wanting,  and  a  pellicle  of  a  dark 
brown  substance  alone  points  out  the  configuration 
of  the  original  (Tab.  42). 

Not  only  are  the  skeletons  and  feathers  of  birds 
found  in  the  tertiary  strata,  but  even  the  eggs  of 


TAB.  42.— FOSSIL  BIRD,  FROM  MONTMARTRE. 

aquatic  species  occur  in  the  lacustrine  limestone  of 
Auvergne.      I  have  already  noticed  that  eggs  of 


§  33.  FOSSIL  ANIMALS  OF  PARIS.  239 

turtles  are  daily  in  the  course  of  fossilization  on  the 
shores  of  the  Isle  of  Ascension. 

33.    FOSSIL    ANIMALS    OF    PARIS.  —  We   have 
next  to  consider  the  fossil  remains  of  the  mammalia 
whose  skeletons  were  entombed  in  the  mud  of  the 
waters  which  formerly  occupied  the  area  of  Paris, 
and  which  the  genius  of  Cuvier  has  again,  as  it  were, 
called  into  existence.     The  forms  of  these  extinct 
creatures  are  now  as  familiar  to  us  as  our  domestic 
animals,  and  even  the  names  of  palaotheria  and 
anoplotheria  are  almost  become  household  words. 
The  gypsum  quarries  which  are  spread  over  the 
flanks  of  Montmartre  have  long  been  known  to  afford 
fossil  bones ;  but,  although  specimens  occasionally 
attracted  the  notice  of  the  naturalists  of  Paris,  and 
collections  were  formed,  yet  no  one  appears  to  have 
suspected  the  mine  of  wonders  which  the  rocks  con- 
tained, till  the  curiosity  of  Cuvier  was  awakened  by 
the  inspection  of  a  large  collection  of  these  bones, 
after  he  had  successfully  applied  the  laws  of  com- 
parative anatomy  to  the  investigation  of  the  fossil 
elephants  and  mammoths.     He  had  previously  paid 
little  or  no  attention  to  the  partial  accounts  of  fossil 
bones  found  in  the  vicinity  of  Paris,  although  in 
1768,   Guettard   had  figured  and  described   many 
bones  and  teeth.      Cuvier  now,  however,  perceived 
that  a  new  world  was  open  to  his  researches,  and  he 
soon,  by  zeal  and  energy,  obtained  an  extensive  coU 
lection,  and  found  himself  (to  use  his  own  expres- 
sion) in  a  charnel-house,  surrounded  by  a  confused 


240  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

mass  of  broken  skeletons  of  a  great  variety  of  ani- 
mals. To  arrange  each  fragment  in  its  proper 
place,  and  to  restore  order  to  these  heaps  of  ruins, 
seemed  at  first  a  hopeless  task ;  but  a  knowledge  of 
the  immutable  laws  by  which  the  organization  of 
animal  existence  is  governed,  soon  enabled  him  to 
assign  to  each  bone,  and  even  fragment  of  bone,  its 
proper  place  in  the  skeleton  ;  and  the  forms  of  beings 
hitherto  unseen  by  mortal  eye  arose  before  him* 
"  I  cannot,"  says  this  illustrious  philosopher,  in  all 
the  enthusiasm  of  successful  genius,  "  express  mv 
delight  on  finding  how  the  application  of  one  prin- 
ciple was  instantly  followed  by  the  most  trium- 
phant results.  The  essential  character  of  a  tooth, 
and  its  relation  to  the  skull,  being  determined,  im- 
mediately all  the  other  elements  of  the  fabric  fell 
into  their  places ;  and  the  vertebrae,  ribs,  bones  of 
the  legs,  thighs,  and  feet,  seemed  to  arrange  them- 
selves even  without  my  bidding,  and  precisely  in 
the  manner  which  I  had  predicted."  The  prin- 
ciples of  comparative  anatomy  enunciated  in  the 
second  lecture  will  have  prepared  you  for  this  re- 
sult ;  and  I  therefore  need  not  dwell  on  the  appli- 
cation of  the  laws  of  co-relation  of  structure  by 
which  the  animals  of  the  Paris  basin  have  been 
restored.  This  group  of  figures,  (Tab.  4-3)  from 
Cuvier's  restorations,  is  indeed  a  splendid  triumph 
of  Palaeontology. 

The  examination  of  the  fossil  teeth  at  once  showed 
that  the  animals  were  herbivorous,  the  enamel  and 


§33. 


FOSSIL  ANIMALS  OF  PARIS. 


241 


ivory  being  disposed  in  the  manner  already  ex- 
plained (page  132);  the  crown  of  the  tooth  is  com- 
posed of  two  or  three  simple  crescents,  as  in  certain 


TAB.  43.— ANIMALS  OF  THE  TERTIARY  EPOCH. 

Fig.  1.  Anoplotherium  gracile.    2.  Palaeotherium  magnum.    3.  P.  minus. 
4.  Anoplotherium  commune. 

pachydermata  ;  thus  differing  from  the  ruminants, 
which  have  double  crescents,  and  each  four  lines  of 
enamel.  Following  out  the  inquiry,  Cuvier  at  length 
established  that  the  great  proportion  of  bones  and 
teeth  belonged  to  two  extinct  genera  of  pachyder- 
mata, which  bear  an  affinity  to  the  tapir,  rhinoceros, 
and  hippopotamus.  Almost  every  one  is  familiar 
with  the  form  and  habits  of  the  two  last  animals  ; 
but  the  tapir  is  not  so  well  known.  Of  this  genus 
there  are  several  living  species,  all  natives  of  tropi- 
cal climes.  The  Malay  tapir  (a  stuffed  specimen 
of  which  is  placed  on  the  lobby  of  the  British 


242  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

Museum,)  sometimes  attains  eight  feet  in  length, 
and  six  in  circumference.  It  has  a  flexible  pro- 
boscis, a  few  inches  long ;  its  general  appearance 
is  heavy  and  massive,  resembling  that  of  the  hog. 
The  eyes  are  small,  the  ears  roundish  ;  the  skin  is 
thick  and  firm,  and  covered  with  stout  hair;  the 
tail  short.  It  inhabits  the  banks  of  lakes  and  rivers, 
and  has  been  observed  to  walk  under  water,  but 
never  to  swim.* 

34.  PALJEOTHERIA,  AND  ANOPLOTHERIA. — 
These  fossil  animals  are  divided  into  the  genera 
palseotherium  (ancient  wild  beast] ;  and  anoplo- 
therium  (unarmed  wild  beast),  so  named  from  the 
absence  of  canine  teeth.  I  will  now  describe  the 
species  here  figured. 

PALJEOTHERIUM  MAGNUM,  fig.  2.  This  animal 
was  of  the  size  of  a  horse,  but  more  thick  and 
clumsy ;  it  had  a  massive  head,  and  short  extremi- 
ties. It  was  like  a  large  tapir,  but  with  differences 
in  the  teeth,  and  a  toe  less  on  the  fore  feet.  It  must 
have  been  from  four  to  five  feet  in  height,  which 
is  about  equal  to  that  of  the  rhinoceros  of  Java. 
From  the  conformation  of  the  nasal  bones,  no  doubt 
can  exist  of  its  having  been  furnished  with  a  short 
proboscis,  or  trunk. 

PAL^OTHERIUM  MINUS,  fig.  3.  Of  the  size  of 
the  roebuck.  This  creature  had  light  and  slender 
limbs,  with  the  general  configuration  of  the  tapir. 

ANOPLOTHERIUM  GRACILE,  fig.  1.    This  animal, 
*  Griffiths'  Animal  Kingdom,  vol.  iii.  p.  434. 


§  34.  PAL^EOTHERIA  AND  ANOPLOTHERIA.  243 

to  which  Cuvier  gave  the  narae  of  gracile,  from 
its  elegant  proportions,  was  of  the  size  and  form  of 
a  gazelle,  and  must  have  lived  after  the  manner  of 
the  deer  and  antelopes. 

ANOPLOTHERIUM  COMMUNE,  fig.  4 ;  was  of  the 
height  of  a  wild  boar,  but  of  a  more  elongated 
form,  and  had  a  long  and  thick  tail  like  a  kangaroo, 
the  feet  having  two  large  toes  like  the  ruminants. 
It  seems  probable  that  it  could  swim  with  facility, 
and  frequented  the  lakes,  in  the  beds  of  which  its 
bones  were  deposited. 

More  than  fifty  genera  of  extinct  mammalia  have 
been  discovered  in  the  older  tertiary,  and  their  cha- 
racters determined  by  Baron  Cuvier.  Some  are 
related  to  the  animals  we  have  just  described ;  as 
the  anthracotherium,  (so  named  from  the  discovery 
of  its  remains  in  the  anthracite,  or  lignite  of  Cadi- 
bona,)  which  held  an  intermediate  place  between 
the  hog  and  hippopotamus.  Six  or  seven  species 
of  carnivora,  an  opossum,  a  squirrel,  dormouse,  &c. 
have  also  been  found  in  the  Paris  basin. 

In  the  miocene  strata  of  Touraine  and  of  Darm- 
stadt, there  is  an  intermixture  of  the  remains  of  the 
above  extinct  mammalia  with  those  of  the  mastodon, 
and  of  genera  which  still  exist.  Mr.  Murchison  has 
discovered  in  Bavaria,  bones  of  the  palseotherium, 
anoplotherium,  anthracotherium,  mastodon,  rhino- 
ceros, hippopotamus,  ox,  horse,  bear,  &c.  in  lacus- 
trine deposits,  associated  with  fresh-water  and  land 
shells. 

R  2 


244                      THE  WONDERS  OF  GEOLOGY.               LECT.  III. 
35.     FOSSIL     QUADRUMANA     OR    MONKEYS. At 

Sausan,  in  the  department  of  Gers,  are  tertiary 
strata,  abounding  in  remains  of  the  rhinoceros, 
horse,  palaeotherium,  anoplotherium,  and  other 
mammalia.  M.  Lastel  has  discovered  a  jaw  of  a 
monkey,  which,  from  its  proportions,  must  have  be- 
longed to  an  animal  about  three  feet  in  height.  The 
molar  teeth  in  the  specimen  are  worn,  and  very 
closely  resemble  those  of  a  man  of  middle  age, 
reduced  to  half  their  natural  size.  Another  fossil 
monkey  has  been  found  in  the  Sub-Himalaya  hills 
near  the  Sutlej,  by  Captain  Cautly,  associated  with 
remains  of  mastodons,  elephants,  crocodiles,  turtles, 
&c.  This  specimen  is  the  right  half  of  the  upper 
jaw,  to  which  a  portion  of  the  orbit  of  the  eye  re- 
mains attached,  and  this  alone  is  sufficient  to  enable 
an  anatomist  to  determine  the  nature  of  the  ori- 
ginal, the  orbits  of  the  quadrumana  being  peculiar. 
Without  entering  upon  details  uninteresting  to  the 
general  inquirer,  it  may  be  stated  that  evidence  is 
thus  afforded  of  the  existence  of  a  gigantic  species 
of  monkey,  contemporaneously  with  the  pachy- 
dermata  whose  fossil  remains  occur  in  the  Sub- 
Himalayas.  The  important  fact  is  therefore  now 
established,  that  animals  of  that  type  of  organization 
which  most  nearly  resembles  the  human,  existed  in 
the  ancient  tertiary  epochs.* 

*  THE  QUADRUMANA. — These  animals  come  nearest  to  man 
in  the  form  and  proportion  of  their  skeleton,  and  of  their  sepa- 
rate bones ;  in  the  general  disposition  of  their  muscular  system, 


§  36.       TERTIARY  STRATA  OF  AIX,  IN  PROVENCE.       245 

36.  TERTIARY  STRATA  OF  AIX,  IN  PROVENCE. 
(See  PI.  9,  section  iii.) — A  group  of  tertiary  strata, 
remarkable  as  well  for  their  mineralogical  character 
as  for  the  organic  remains  which  they  contain, 
occurs  near  Aix,  a  town  in  Provence,  which  is  situ- 
ated upon  a  thick  deposit  of  tertiary  conglomerate. 
The  series  on  the  northern  side  of  the  valley  con- 
sists of — 1.  Tertiary  breccia,  (see  PI.  9,  fig.  3,) 
lying  unconformably  on  the  secondary  rocks  of 
oolite  and  green  sand,  which  are  nearly  vertical. 
2.  Marl,  with  fishes  and  insects.  3.  Gypsum  and 
gypseous  marls,  with  fishes  and  insects  ;  leaves  of 

and  its  adaptation  for  a  semi-erect  position  of  the  body ;  in 
their  great  cerebral  organization,  the  perfection  and  equable 
development  of  their  senses ;  their  intellectual  capacity,  and 
complicated  instincts.  These  most  elevated  of  all  inferior 
animals  are  fitted  to  select,  obtain,  and  digest  the  succulent 
ripe  fruits  of  trees,  and  are  destined  to  inhabit  the  rich  and 
shady  forests  of  tropical  climates.  They  leave  to  the  squirrels 
and  the  sloths  the  buds  and  leaves ;  to  the  ponderous  elephant 
and  rhinoceros  the  branches  and  the  stems  ;  and  to  the  beavers, 
and  other  rodentia,  the  dark  bark  of  the  trees.  Their  delicate 
organization  is  adapted  only  for  the  richest  products  of  the 
vegetable  kingdom  ;  and  the  soft  and  nutritious  quality  of  their 
food  is  suitable  to  the  broad  enamelled  crowns  of  their  molar 
teeth,  which  are  studded  with  rounded  tubercles :  their  stomach 
is  simple.  With  a  high  cerebral  and  muscular  development, 
corresponding  with  their  elevated  rank  in  the  scale  of  beings, 
and  the  position  of  their  food,  they  are  the  most  agile  and  sportive 
of  all  mammalia  ;  and  they  are  provided  with  prehensile  organs 
at  every  point ;  their  teeth,  tail,  feet,  and  hands  assist  in  their 
agile  movements,  and  in  their  boundings  from  branch  to  branch, 
and  from  tree  to  tree. — Dr.  Grant's  Lectures  on  Comparative 
Anatomy* 


246 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


palms,  and  other  plants  ;  fresh-water  univalve  and 
bivalve  shells,  particularly  a  species  of  cyclas  in 
great  abundance.  The  cyclas  inhabits  lakes  and 
marshes,  and  therefore  positively  denotes  the  lacus- 
trine character  of  the  deposits.  4.  Fresh-water 
limestone.  To  the  south,  extending  towards  Tou- 
lon, are  lacustrine  strata  of  red  marl,  with  compact 
limestone  inclosing  shells,  gyrogonites,  &c.  Still 
farther  to  the  south,  beds  of  grey  fresh-water  lime- 
stone appear ;  and  at  Fuveau,  (see  the  section, 
PI.  9,  fig.  3,)  a  series  of  blue  limestone,  shale,  and 
coal,  which  is  extensively  worked.  Fresh-water 


TAB.  44.— FOSSIL  FISH,  FROM  Aix. 

(Smerdis  minutus.) 
(Drawn  by  Miss  Jane  Allnutt.) 

shells,  seed  vessels  of  charce,  and  other  vegetable 
remains,  occur  in  abundance  in  the  coal-beds  and 
intermediate  layers  of  shale.  The  section  employed 


§  37.  FOSSIL  INSECTS.  247 

to  illustrate  this  description  is  copied  from  a  rough 
sketch  made  by  Mr.  Lyell  on  the  spot,  when  he  first 
visited  this  interesting  locality  ;  and  which  I  greatly 
value  on  that  account. 

The  marls,  as  you  may  perceive,  in  this  extensive 
suite  of  specimens,  collected  by  Messrs.  Lyell  and 
Murchison,  (whose  admirable  Memoir*  on  these 
strata  is  of  high  interest,)  are  very  finely  laminated, 
and  contain  insects  and  fishes  in  a  remarkable  state 
of  preservation.  The  fishes  are  very  numerous; 
one  small  species  in  particular  (smerdis  minutus^ 
Tab.  44-,)  is  found  grouped  together  in  every  va- 
riety of  form  and  position. 

37.  FOSSIL  INSECTS. — But  the  fossil  insects  are 
the  most  extraordinary  relics,  appearing  as  fresh  as 
if  enveloped  but  yesterday.  This  beautiful  example, 
presented  to  me  by  Mrs.  Murchison,  shows  the  ex- 
quisite preservation  of  these  delicate  objects.  A 
few  of  the  most  interesting  forms  are  here  delineated 
on  a  slightly  enlarged  scale,  from  the  plate  accom- 
panying the  paper  to  which  I  have  referred. -f 

All  the  insects  belong  to  existing  genera,  and 
only  one  species  is  aquatic. J  The  anterior  tarsi 
are  generally  obscure,  or  distorted;  but  in  some 
specimens  the  claws  are  visible,  and  the  sculp- 
ture, and  even  a  degree  of  local  colouring  are 

*  On  the  Freshwater  Formation  of  Aix,  in  Provence,  by 
C.  Lyell,  and  R.  I.  Murchison,  Esqrs. 

t  Jameson's  Edinburgh  Journal,  for  1829.     PI.  VI. 
\  Principles  of  Geology,  vol.  iii.  p.  211. 


248 


THE  WONDERS  OF  GEOLOGY. 


LECT.  III. 


preserved.  The  nerves  of  the  wings  in  the  diptera, 
and  even  the  pubescence  on  the  head,  are  distinctly 
seen.  Several  of  the  beetles  have  the  wings  ex- 


TAB.  45. — FOSSIL  INSECTS  FROM  Aix,  IN  PROVENCE. 

Fig.  1.  Tettigonia  spumaria.  2.  Mycetophila,  imbedded  while  in  the 
act  of  walking ;  the  articulations  of  the  body  distended  by  pressure. 
3.  Lathrobium.  4.  Allied  to  Penthetria  holosericea.  The  hinder  legs 
are  broken  off,  and  one  of  them  is  reversed,  so  that  the  tarsi  nearly 
touch  the  thigh ;  the  palpi  are  long  and  perfect ;  the  antennce  remark- 
ably distinct.  5.  Liparus,  resembling  L.  punctatus. 

tended  beyond  the  elytra)  as  if  they  had  fallen  into 
the  water  while  on  the  wing,  and  had  made  an 
effort  to  escape  by  flight.  M.  Marcel  de  Serres 
has  enumerated  nearly  seventy  genera  of  insects, 


§  37.  FOSSIL  INSECTS.  249 

and  a  few  arac/mides,  or  spiders.  The  most  curious 
fact  is,  that  some  of  the  insects  are  identical  with 
species  which  now  inhabit  Provence.  It  seems  pro- 
bable that  these  insects  were  brought  together  from 
different  localities  by  floods,  and  mountain  streams ; 
yet,  as  Mr.  Curtis  observes,  all  of  them  might  have 
inhabited  moist  and  shady  forests.  The  laminated 
marls  contain  also  the  coverings  of  a  fresh-water 
Crustacea,  called  cypris,  which  swarms  in  our  pools 
and  stagnant  waters,  and  must  be  familiar  to  all 
who  have  seen  the  exhibition  of  the  oxy-hydrogen 
microscope  ;  living  specimens  being  commonly 
shown,  and  appearing  somewhat  like  the  head  and 
feet  of  a  flea  protruding  from  an  oval  case  or 
shield,  and  swimming  by  means  of  their  fine  cilia, 
which  resemble  pencils  of  hair.  These  Crustacea 
shed  their  cases,  some  of  which  are  silicious  and 
others  calcareous,  annually,  and  the  surface  of  the 
mud  spread  over  the  bottoms  of  lakes  is  often 
strewed  with  their  relics.  The  marls  of  Aix,  as 
well  as  of  many  other  fresh-water  formations,  abound 
in  fossil  cyprides,  which  sometimes  constitute  entire 
seams  or  laminae,  that  alternate  with  the  marl.  The 
seed-vessels  of  the  chara,  a  common  plant  in  our 
ditches  and  ponds,  also  occur  in  profusion ;  they 
were  formerly  supposed  to  be  shells,  and  from  their 
peculiar  structure  received  the  name  of  gyrogonites, 
which  they  still  bear,  although  their  real  nature 
has  long  since  been  ascertained.*  In  conclusion, 

See  an  Essay  on  the  fresh-water  marls  of  Scotland,  by 
Mr.  Lyell. 


250  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

Mr.  Lyell  observes,  "  that  this  tertiary  series  differs 
essentially  from  that  of  the  London  and  Paris 
basins.  The  great  development  of  regular  beds 
of  blue  limestone  and  shale,  the  quality  and  ap- 
pearance of  the  coal,  and  the  thickness  of  the 
compact  grey,  brown,  and  black  argillaceous  lime- 
stones and  sandstones,  give  them  the  aspect  of  the 
most  ancient  of  our  secondary  rocks  ;  and  it  is 
only  by  the  peculiar  species  of  fluviatile  and  lacus- 
trine shells,  the  seed-vessels  of  the  charse,  £c.  that 
the  comparatively  recent  date  of  the  whole  group 
is  demonstrated." 

38.  LACUSTRINE  FORMATION  OF  (ENINGEN. — 
Among  the  tertiary  lacustrine  formations  on  the 
continent,  there  is  one  so  much  celebrated  for  its 
organic  remains,  that  I  will  offer  a  few  remarks  on  its 
peculiar  characters.  CEningen,  near  Constance,  has 
for  centuries  been  known  to  contain  fossil  remains 
of  great  beauty  and  interest.  A  short,  but  graphic, 
memoir  by  Mr.  Murchison,*  presents  in  a  few  pages 
the  history  of  this  ancient  lake.  The  Rhine,  in 
its  course  from  Constance  to  Schaffhausen,  flows 
through  a  depression  of  the  tertiary  marine  forma- 
tion, known  by  the  name  of  Molasse,  which  forms 
hills  on  both  sides  of  the  river,  of  from  700  to  900 
feet  in  height.  In  a  depression  or  basin  of  this 
molasse,  is  a  series  of  strata  composed  of  marls, 
and  cream-coloured,  fine-grained,  fetid  limestone, 
with  laminated  white  marl-stone,  forming  a  total 

*  On  a  fossil  Fox  found  at  CEningen,  by  R.  I.  Murchison, 
Esq.,  Pres.  G.S.  &c.  Geological  Transactions,  1832. 


§  39.  FOSSIL  FISHES  OF  MONTE  BOLCA.  251 

thickness  of  thirty  or  forty  feet.  In  the  marl-stone, 
leaves  and  stems  of  plants,  insects,  shells,  Crustacea, 
fishes,  turtles,  a  large  aquatic  salamander,  birds,  and 
a  perfect  skeleton  of  a  fox,  have  been  discovered. 
The  fox  was  obtained  by  Mr.  Murchison,  for  whom 
I  developed  it,  and  removed  the  stone  so  as  to 
expose  the  entire  skeleton :  this  extraordinary  fossil, 
which  does  not  differ  in  its  osteology  from  the  recent 
species,  is  figured  and  described  in  the  Geological 
Transactions  for  1832.  A  tortoise, 'three  feet  in 
length,  with  the  head,  neck,  tail,  and  three  of  the 
paws,  well  preserved,  has  since  been  discovered. 
Mr.  Murchison  concludes  that  these  fresh- water  de- 
posits are  the  contents  of  a  lake,  belonging  to  the 
newer  pliocene  epoch,  but  that  the  period  of  their 
formation  must  have  long  preceded  the  present 
condition  of  the  country,  the  Rhine  having  subse- 
quently worn  a  channel  through  them  to  the  depth 
of  several  hundred  feet. 

39.  FOSSIL  FISHES  OF  MONTE  BOLCA. — I  will 
here  notice  another  interesting  assemblage  of  ter- 
tiary strata — the  celebrated  ichthyolite  quarries  of 
Monte  Bolca — and  then  proceed  to  the  consider- 
ation of  the  effects  of  volcanic  action  during  the 
geological  epochs  embraced  in  this  discourse. 
Monte  Bolca  is  situated  on  the  borders  of  the 
Veronese  territory,  about  fifty  miles  NN.W.  of  the 
lagunes  of  Venice,  and  forms  part  of  a  range  of  hills 
of  moderate  elevation  ;  volcanic  deposits  abound  in 
the  neighbouring  Vicentin,  and  the  summit  of  the 


252  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

hill  is  capped  with  basalt.*  It  is  principally  com- 
posed of  argillaceous  and  calcareous  strata,  with 
beds  of  a  cream-coloured  fissile  limestone,  which 
readily  separates  into  laminae  of  moderate  thickness, 
and  abounds  in  fishes  in  the  most  beautiful  state  of 
preservation.  They  are  all  compressed  flat,  but  the 
scales,  bones,  and  fins  remain  ;  their  colour  is  a 
deep  brown,  thus  admirably  contrasting  with  the 
limestone  in  which  they  are  imbedded.  Several 
hundred  distinct  species  are  supposed  to  be  con- 
tained in  these  quarries,  and  thousands  of  specimens 
have  been  collected ;  according  to  M.  Agassiz,  all 
the  species,  though  related  to  the  recent,  are  extinct. 
From  the  immense  quantities  which  occur  in  so 
limited  an  area,  it  seems  probable  that  the  limestone 
in  which  they  are  imbedded  was  erupted  into  the 
ocean  in  a  fluid  state  by  volcanic  agency ;  and  that 
the  fishes  were  thus  suffocated,  and  surrounded  by 
the  calcareous  mass.  Nor  is  this  hypothesis  without 
support,  for  on  the  appearance  of  a  volcanic  island 
in  the  Mediterranean,  a  few  years  since,  hundreds 
of  dead  fishes  were  seen  putrid  and  floating  in  the 
waters  ;  and  it  cannot  be  doubted  that  shoals  of 
fishes  might  at  the  same  time  have  been  enveloped 
in  the  volcanic  matter  at  the  bottom  of  the  sea,  and 
become  compressed  and  preserved ;  when  the  mud 
which  envelopes  them  is  consolidated,  and  the  bed 
of  the  Mediterranean  elevated  above  the  waters, 

*  Organic  Remains  of  a  Former  World,  vol.  iii.  p.  247. 


§  40.  TERTIARY  VOLCANOES  OF  FRANCE.  253 

these  fishes  may  resemble  the  ichthyolites  of  Monte 
Bolca.* 

40.  TERTIARY  VOLCANOES  OF  FRANCE. — In  the 
former  lecture  I  alluded  to  volcanic  action  as  being 
still  in  activity,  and  as  having  taken  place  in  more 
ancient  periods ;  and  we  have  abundant  proof  that 
during  the  immense  lapse  of  time  comprehended 
between  the  earliest  and  the  latest  of  the  tertiary 
formations,  the  internal  fires  of  our  globe  were  not 
dormant.  I  have  already  had  occasion  to  observe, 
how  rarely  the  former  geographical  relations  of  a 
country  are  preserved,  and  that  although  we  may 
be  able  to  pronounce  with  certainty  that  this  spot 
was  once  dry  land, — that  there  flowed  a  river, — 
that  here  is  the  bed  of  an  ancient  sea — yet  we  can 
seldom  ascribe  limits  to  the  one,  or  trace  the  boun- 
daries of  the  other.  But  there  is  one  remarkable 
exception  —  a  district,  where  the  most  important 
and  striking  geological  mutations  have  taken  place, 
and  yet  the  area  of  those  changes  still  preserves  its 
ancient  physical  geography — that  district  is  Au- 
vergne,  a  province  in  central  France. 

Nearly  a  century  since,  two  French  academicians, 
MM.  Guettard  and  Malesherbes,  on  their  return 
from  an  exploration  of  Vesuvius,  arrived  at  Monte- 
limart,  a  small  town  on  the  left  banks  of  the  Rhone, 
where  Faujas  St.  Fond,  a  distinguished  naturalist, 
was  sojourning.  These  savans  were  struck  with 

*  See  Lecture  VIII. 


254  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

the  pavements  of  the  streets,  which  were  formed  of 
shore  joints  of  basaltic  columns,  placed  perpendicu- 
larly in  the  ground  ;  and  upon  inquiry  they  found, 
that  the  stones  were  brought  from  the  neighbouring 
mountains  of  the  Vivarais.  This  information  induced 
them  to  survey  the  country ;  and  upon  arriving  at 
Clermont,  a  town  with  about  30,000  inhabitants, 
the  capital  of  Auvergne,  they  were  satisfied  that  the 
whole  region  was  of  volcanic  origin  ;  for  in  the 
vicinity  of  the  town  they  discovered  currents  of 
lava,  black  and  rugged  as  those  of  Italy,  descending 
uninterruptedly  from  some  conical  hills  of  scoriae, 
which  still  preserved  the  form  of  craters.  "  To 
those  who  now  visit  central  France,  and  see  on 
all  sides  the  most  unequivocal  marks  of  volcanic 
agency  —  the  numerous  hills  formed  entirely  of 
loose  cinders,  and  porous  and  diversified  as  if  just 
thrown  from  a  furnace,  surrounded  by  plains  of 
black  rugged  lava,  on  which  even  the  lichen  almost 
refuses  to  vegetate, — it  appears  scarcely  credible, 
that  previous  to  the  last  half  century,  no  one  had 
thought  of  attributing  these  marks  of  desolation  to 
the  only  powers  in  nature  capable  of  producing 
them.  This,  however,  is  perfectly  natural,  and 
not  without  examples.  The  inhabitants  of  Hercu- 
laneum  and  Pompeii  built  their  houses  with  the 
lava  of  Vesuvius,  ploughed  up  its  scoriae  and  ashes, 
and  ascended  its  crater,  without  dreaming  of  their 
neighbourhood  to  a  volcano  which  was  to  give  the 
first  proof  of  its  energies  by  burying  them  beneath 


§41.  EXTINCT  VOLCANOES  OF  AUVERGNE.  255 

its  eruptions,  The  Catanians  regarded  as  a  fable 
all  mention  of  the  former  activity  of  Etna,  when, 
in  1669,  half  their  town  was  overwhelmed  by  its 
lava  currents."* 

41.  EXTINCT  VOLCANOES  OF  AUVERGNE. — The 
country  which  is  the  site  of  the  extinct  volcanoes  to 
which  I  am  about  to  call  your  attention,  may  be 
described  as  a  vast  plain,  situated  in  the  department 
of  the  Limagne  d'Auvergne :  it  is  so  remarkable 
for  its  fertility,  that  it  is  called  the  Garden  of 
France ;  a  quality  attributable  to  the  detritus  of 
volcanic  rocks,  which  enters  into  the  composition 
of  the  soil.  It  is  inclosed  on  the  east  and  west  by 
two  parallel  ranges  of  gneiss  and  granite.  Its 
average  breadth  is  twenty  miles,  its  length  between 
forty  and  fifty,  and  its  altitude  about  1,200  feet 
above  the  level  of  the  sea.  The  surface  of  this 
plain  is  formed  of  alluvial  deposits,  composed  of 
granitic  and  basaltic  pebbles,  and  boulders,  reposing 
on  a  substratum  of  limestone.  Hills,  of  various 
elevations,  composed  of  calcareous  rocks,  are  scat- 
tered over  the  plain;  and  the  river  Allier  flows 
through  the  district,  over  beds  of  limestone  or  sand- 
stone, except  where  it  has  excavated  a  channel  to 

•  Geology  of  Central  France,  by  G.  Poulett  Scrope,  Esq. 
F.R.S.,  1827.  Mr.  Bakewell  was  the  first  English  geologist 
who  directed  attention  to  this  remarkable  district;  (Travels  in 
the  Tarentaise,  by  Robert  Bakewell,  Esq.  2  vols.  8vo.  1823  ;) 
subsequently  Dr.  Daubeny,  Messrs.  Scrope,  Lyell,  and  Mur- 
chison,  have  severally  published  highly  interesting  treatises  on 
the  subject. 


256  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

the  foundation-rock  of  granite.  The  hills  composed 
of  calcareous  alluvial  deposits  are  the  remains  of  a 
series  of  beds,  which  once  constituted  an  ancient 
plain,  at  a  higher  elevation  than  the  present.  Many 
are  surmounted  by  a  crest  or  capping  of  basalt,  to 
which  their  preservation  is  probably  attributable  ; 
others  have  escaped  destruction  from  being  pro- 
tected by  horizontal  layers  of  a  durable  limestone, 
which  I  shall  presently  describe.  We  have,  then, 
as  the  ground  plan  of  the  district,  an  extensive 
plain,  chequered  with  low  hills  of  fresh- water 
limestone,  which  are  capped  with  compact  lava 
(Plate  VIII.  figs.  in.  iv.)  ;  the  boundaries  of  the 
plain  being  formed  of  ranges  of  primary  rocks, 
3,000  feet  in  altitude.  To  the  westward  the  lime- 
stone disappears,  and  a  plateau  of  granite  rises 
to  a  height  of  about  1,600  feet  above  the  valley 
of  Clermont,  being  3,000  feet  above  the  level  of 
the  sea.  This  supports  a  chain  of  volcanic  cones 
and  dome  -  shaped  mountains,  about  seventy  in 
number,  varying  in  altitude  from  500  to  1,000  feet 
from  above  their  bases,  and  forming  an  irregular 
range  nearly  twenty  miles  in  length,  and  two  in 
breadth.  The  highest  point  of  this  range  is  the 
Puy  de  Dome,  which  is  4,000  feet  above  the 
level  of  the  sea  (Plate  VIII.  fig.  u.  4),  and  is  com- 
posed entirely  of  volcanic  matter  ;  it  possesses  a 
regular  crater,  300  feet  deep,  and  nearly  1,000 
feet  in  circumference.  Many  of  these  cones  retain 
the  form  of  well-defined  craters,  and  their  lava 


§42.  CRATER  OF  PUY  DE  COME.  257 

currents   may    be    traced   as   readily   as   those   of 
Vesuvius. 

42.  CRATER  OF  PUY  DE  COME. — One  of  the 
most  remarkable  cones  is  the  Puy  de  Come,  which 
rises  from  the  plain  to  the  height  of  900  feet ; 
its  sides  are  covered  with  trees,  and  its  summits 
present  two  distinct  craters,  one  of  which  is  250 
feet  in  depth.  A  stream  of  lava  may  be  seen  to  have 
issued  out  from  the  base  of  the  mountain,  which  at 
a  short  distance,  from  having  been  obstructed  by  a 
mass  of  granite,  has  separated  into  two  branches ; 
these  can  be  traced  along  the  granitic  platforms,  and 
down  the  side  of  a  hill  into  an  adjacent  valley,  where 
they  have  dispossessed  a  river  of  its  bed,  and  con- 
strained it  to  work  out  a  fresh  channel  between  the 
lava  and  the  granite  of  the  opposite  bank.  Another 
cone  rises  to  the  height  of  1,000  feet  above  the 
plain,  having  a  crater  nearly  600  feet  in  vertical 
depth,  and  a  lava  current,  which  first  falls  down  a 
steep  declivity,  and  then  rolls  over  the  plain  in 
hilly  waves  of  black  and  scorified  rocks.  In  one 
part  of  this  volcanic  group  is  a  circular  system  of 
cones,  apparently  the  produce  of  several  rapidly 
succeeding  eruptions.  "  The  extraordinary  cha- 
racter of  this  scene  impresses  it  for  ever  on  the 
memory ;  for  there  is,  perhaps,  no  spot,  even  among 
the  PhlegraBan  fields  of  Italy,  which  more  strikingly 
displays  the  characters  of  volcanic  desolation.  Al- 
though the  cones  are  partially  covered  with  wood 
and  herbage,  yet  the  sides  of  many  are  still  naked ; 
s 


258  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

and  the  interior  of  their  broken  craters,  rugged, 
black,  and  scorified,  as  well  as  the  rocky  floods  of 
lava  with  which  they  have  loaded  the  plain,  have  a 
freshness  of  aspect,  such  as  the  products  of  fire 
alone  could  have  so  long  preserved,  and  offer  a 
striking  picture  of  the  operation  of  this  element  in 
all  its  most  terrible  energy."*  A  description  of 
the  accompanying  sketches-)-  will  serve  to  illustrate 
these  remarks. 

Plate  VIII.  fig.  in.  The  environs  of  Clermont. 
The  town  is  seen  on  the  plain  or  basin,  which  has 
been  excavated  by  diluvial  agency,  since  the  de- 
position of  the  strata  which  form  the  surrounding 
hills.  In  front  is  a  basaltic  peak  (coloured  green), 
crowned  by  the  Castle  of  Montrognon  ;  and  beyond 
are  basaltic  platforms  on  hills  of  limestone.  In 
the  distance  is  the  primary  escarpment,  forming 
part  of  the  boundary  of  the  volcanic  district. 

Plate  VIII.  fig.  ii.  Part  of  the  southern  volcanic 
chain  of  Puys,  exhibiting  the  broken  craters  of 
Chaumont;  from  the  bases  of  several,  lava  currents 
are  seen  to  have  issued.  No.  1,  Montchal ;  2, 
Puys  de  Montgy  ;  3,  Monjughat ;  4,  Mont  Dome 
in  the  distance. 

Plate  VIII.  fig.  iv.  represents  hills  of  secondary 
Jura  limestone,  capped  by  basalt  (coloured  green). 
These  crests  are  the  terminations  of  lava  currents, 

*  Scrope's  Geology  of  Central  France, 
•j-  The  delineations  are  reduced  from  the  elaborate  and  beau- 
tiful drawings  of  Mr.  Scrope. 


§  43.  MONT  DOR.  259 

that  once  extended  over  the  whole  area,  covering 
a  platform  of  primary  rocks,  and  flowing  on  to  the 
secondary  strata,  which,  in  this  part  of  Ardeche, 
constitute  an  elevated  limestone  district. 

This  region  affords  a  striking  illustration  of 
the  erosion  of  the  surface  of  a  country  by  alluvial 
action.  The  thickness  of  the  volcanic  mass  is  be- 
tween 300  and  400  feet;  it  is  composed  of  two 
distinct  beds  of  basalt,  separated  by  a  layer  of 
scoriae  and  volcanic  fragments.  Many  portions, 
both  of  the  upper  and  lower  beds,  are  made  up  of 
well-defined,  vertical,  polygonal  columns.  The 
streams  of  lava  to  which  these  plateaux  belong, 
have  been  traced  for  more  than  thirty  miles ;  they 
rise  in  a  narrow  ridge  across  the  primitive  heights, 
and  then  spread  over,  and  lie  conformably  upon, 
the  secondary  formations.  The  limestone  beneath 
the  basalt  is,  in  some  places,  covered  with  vegetable 
soil,  containing  a  common  species  of  terrestrial 
shell  (  Cyclostoma  elegans).  The  nearly  horizontal 
disposition  of  the  basalt,  its  columnar  structure, 
artd  position  on  the  limestone,  into  which  it  has 
injected  veins  and  dikes,  render  it,  as  Mr.  Scrope 
observes,  very  analogous  to  the  ancient  volcanic 
rocks  of  Ireland,  which  will  be  described  in  a  future 
lecture. 

43.  MONT  DOR. — Before  entering  upon  the  de- 
scription of  the  organic  remains  found  in  the  rocks 
and  strata  we  have  thus  hastily  surveyed,  it  will 
be  necessary  to  notice  another  system  of  extinct 
s2 


260  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

volcanoes,  situated  in  the  same  province,  and  con- 
nected with  the  Puy  de  Dome.  While  in  the  dis- 
trict I  have  just  described,  the  primitive  soil  is 
only  partially  obscured  by  the  volcanic  products,  in 
Mont  Dor,  the  granitic  foundation  is  covered  over 
an  area  of  many  miles  in  extent,  and  the  erupted 
masses  attain  a  considerable  elevation.  Mont  Dor 
is  a  mountainous  tract,  the  highest  portion  of  which 
is  about  6,000  feet  in  altitude.  It  consists  of  a 
group  of  seven  or  eight  rocky  summits,  which  form 
a  zone  a  mile  in  diameter,  the  whole  consisting 
of  a  succession  of  beds  of  volcanic  origin.  It  is 
deeply  channelled  by  two  principal  valleys,  and 
furrowed  by  many  minor  water-courses,  all  origi- 
nating near  the  central  eminence,  and  diverging 
towards  every  point  of  the  horizon.  The  beds  of 
which  this  group  is  composed,  consist  of  scoriae, 
pumice-stone,  trachyte,  and  basalt ;  these  rocks 
dip  off  from  the  central  axis,  and  lie  parallel 
to  the  sloping  flanks  of  the  mountain,  as  is  the 
case  in  Etna,  the  Peak  of  Teneriffe,  and  all  other 
insulated  volcanic  mountains  (see  the  section  of  a 
volcano,  Plate  VIII.  fig.  1).  There  is  no  crater, 
all  vestiges  having  been  destroyed  since  the  ex- 
tinction of  its  fires ;  but  streams  of  lava  may  be 
traced  in  elevated  peaks,  over  a  gorge  which  oc- 
cupies the  very  heart  of  the  mountain,  and  they 
extend  to  a  distance  of  many  miles.  A  remarkable 
natural  section,  worn  by  a  cascade,  at  a  short  dis- 
tance from  the  baths  of  Mont  Dor,  exhibits  the 


§  44.  FRESH- WATER  LIMESTONE.  261 

general  structure  of  the  beds  (PI.  VIII.  fig.  5). 
They  consist  in  a  descending  series  of — 1.  Porphy- 
ritic  trachyte ;  a  volcanic  rock,  160  feet  tn  thick- 
ness. 2.  Arenaceous  tufa.  3.  Columnar  basalt. 
4.  Breccia,  made  up  of  volcanic  fragments,  cemented 
together  by  tufa.  5.  Thick  beds  of  basalt.  6. 
White  ferruginous  tufa,  enveloping  fragments  of 
granite,  basalt,  &c.  This  bed  is  traversed  by  veins 
of  the  overlying  basalt. 

I  may  add,  that  the  volcanic  vents  of  central 
France  are  evidently  of  very  different  ages ;  some 
being  of  immense  antiquity,  while  others  must  be 
of  comparatively  recent  origin,  for  they  have  ex- 
ploded through  the  older  beds  of  basalt. 

44.  FRESH-WATER  LIMESTONE,  AND  ORGANIC 
REMAINS  OF  AuvERGNE. — The  volcanic  rocks  of 
this  district  present  alternations  of  limestone, 
abounding  in  fresh-water  shells  and  other  animal 
remains ;  with  basalt,  scoriae,  and  other  igneous 
productions,  based  on  a  foundation  of  granite. 
These  beds  are  arranged  in  the  following  order, 
beginning  with  the  lowest  or  most  ancient : — 

1st.  Clay,  sand,  and  breccia,  without  organic 
remains. 

2d.  Limestone  and  calcareous  marl,  in  strata 
nearly  horizontal ;  about  900  feet  thick.  These  are 
entirely  of  fresh-water  origin,  and  abound  in  shells 
of  the  genera  potamides,  helix,  planorbis,  and  lym- 
nea,  which  are  known  to  inhabit  lakes  and  rivers. 
Some  of  the  beds  contain  bitumen ;  others  are 


262  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

entirely  made  up  of  the  cases  of  the  caddis-worm 
(Indusia  tubulata),  cemented  together  by  calcareo- 
silicious  matter.  This  specimen,  which  was  in  the 
cabinet  of  Faujas  St.  Fond,  displays  the  characters 
of  this  remarkable  concrete :  it  consists  of  the  tubes 
or  cases  of  the  larva  of  a  species  of  phryganea ; 
similar  remains  have  been  mentioned  as  occurring 
in  abundance  in  the  alluvial  silt  of  Lewes  Levels 
(page  45).  The  tubes  are  formed  by  the  adhesion 
of  shells  to  the  outer  surface  of  the  silken  case 
secreted  by  the  insect ;  these  cases  are  abandoned 
by  the  animal  when  its  metamorphosis  is  completed, 
and  groups  of  them  may  be  seen  in  ditches  or  lakes. 
In  the  fossil  they  have  been  cemented  by  calcareous 
infiltration  into  a  stone,  so  hard  as  to  be  employed 
for  building.  The  attached  shells  are  so  minute, 
that  more  than  a  hundred  are  affixed  to  one  tube, 
and  the  space  of  a  cubic  inch  often  includes  ten  or 
twelve  tubes.  If,  says  Mr.  Scrope,  we  consider 
that  repeated  strata,  of  five  or  six  feet  in  thickness, 
almost  entirely  composed  of  these  tubes,  once  ex- 
tended over  the  whole  plain  of  the  Limagne,  occu- 
pying a  surface  of  many  hundred  square  miles,  we 
may  have  some  idea  of  the  countless  myriads  of 
minute  beings  which  lived  and  died  within  the 
bosom  of  that  ancient  lake.  In  the  limestone, 
associated  with  land  and  fresh-water  shells,  and 
remains  of  vegetables,  are  bones  of  the  palaeothe- 
rium,  anoplotherium,  lagomys,  martin,  dog,  rat, 
tortoise,  crocodile,  serpent,  and  birds,  and  in  which 


§  44.  LIMESTONE  OF  AUVERGNE.  2G3 

the  lava  currents  that  have  flowed  over  them  have 
produced  but  little  change.  This  series  comprises 
also  beds  of  gypseous  and  laminated  marls,  with 
intercalations  of  silicious  limestone,  containing  im- 
pressions of  lake  and  river  shells.  In  some  loca- 
lities, the  fresh-water  limestone  has  an  intermixture 
of  volcanic  matter,  presenting  all  the  characters  of 
a  sediment  slowly  and  tranquilly  deposited  in  a 
lake,  into  which  ashes,  and  fragments  of  rocks  and 
scoria?,  were  projected  by  a  neighbouring  volcano ; 
while  there  are  beds  which  appear  to  have  been 
formed  by  a  violent  intrusion  of  volcanic  matter. 

3d.  Immense  beds  of  volcanic  production,  con- 
sisting of  basalt,  scoriae,  &c.  now  existing  in  sheets 
of  lava,  either  spread  over  the  tabular  masses  of 
fresh-water  limestone,  or  appearing  as  crests  on  the 
summits  of  the  lower  hills.  (Plate  VIII.  fig.  3.) 

4th.  Sand  and  diluvial  gravel,  containing  bones 
of  the  mastodon,  elephant,  hippopotamus,  rhino- 
ceros, tapir,  horse,  boar,  felis,  hyena,  bear,  dog, 
beaver,  hare,  &c. ;  with  these  are  associated  lignite, 
and  other  vegetable  remains.  Some  of  the  beds  of 
limestone  abound  in  seed-vessels  of  the  chara ; 
and  the  laminated  clays  contain  fishes,  and  leaves, 
stems,  &c.  of  reeds  and  other  plants. 

There  are  several  in  crusting  springs  in  Auvergne, 
largely  impregnated  with  carbonic  acid,  which  pour 
out  immense  quantities  of  calcareous  tufa ;  these 
burst  through  the  primary  rocks,  which  form  the 
base  of  the  whole  territory,  and  cover  the  volcanic 


261  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

focus  whence  these  mineral  waters,  in  all  probability, 
originate.  Thermal  springs  are  also  very  numerous 
throughout  this  district. 

45.  SUMMARY  OF  THE  GEOLOGICAL  PHENO- 
MENA OF  AUVERGNE. — In  the  calcareous  and  sili- 
cious  limestones  of  Auvergne,  and  their  associated 
laminated  marls,  gypsum,  lignite,  and  conglomerate, 
we  have  a  general  analogy  with  the  older  fresh- 
water tertiary  formations  of  Paris  and  the  Isle  of 
Wight ;  the  shells  and  plants  being  similar,  and  the 
quadrupeds  of  the  same  genera.  And  if  we  suppose 
the  Paris  basin  to  have  been  elevated  during  the 
active  state  of  neighbouring  volcanoes,  and  that 
successive  streams  of  lava  had  flowed  over  its 
sedimentary  deposits,  we  should  have  a  series  of 
phenomena  resembling  those  of  Auvergne,  with  the 
exception  that  the  presence  of  marine  remains  would 
denote  that  the  basin  had  been  filled  with  salt  water. 
The  facts  submitted  to  our  notice  appear  to  establish 
the  following  sequence  of  physical  events. 

1st.  The  elevation,  after  the  deposition  of  the 
secondary  limestone,  of  the  whole  area  of  the  pri- 
mary rocks  which  form  the  foundation  of  central 
France. 

2dly.  A  period  of  tranquillity,  during  which  fresh- 
water lakes  occupied  the  irregular  hollows  of  the 
district ;  the  neighbouring  country  being  inhabited 
by  palseotheria,  anoplotheria,  and  other  extinct 
mammalia,  whose  bones,  together  with  the  then 
existing  vegetation,  and  the  shells  of  the  lacustrine 


§  45.          GEOLOGICAL  PHENOMENA  OF  AUVERGNE.          265 

mollusca,  were  enveloped  in  the  tranquil  depositions 
going  on  in  the  lacustrine  basins. 

Sdly.  Another  elevation  of  the  district ;  a  new 
system  of  lakes  was  established,  the  country  became 
clothed  with  forests,  and  inhabited  by  large  deer, 
oxen,  rhinoceroses,  and  hyenas,  whose  skeletons 
were  imbedded  in  the  sediments  of  the  waters. 

4thly.  The  volcanoes  became  active ;  explosions 
took  place  through  hundreds  of  vents ;  trachyte  and 
basalt  were  ejected,  and  in  some  places  pierced  the 
fresh-water  deposits,  while  in  others  they  overspread 
them  with  sheets  of  lava.  Vegetation  still  flourished, 
and  the  remains  of  plants  were  entombed  in  the 
volcanic  products. 

5thly.  Another  period  of  tranquillity — the  rivers, 
and  other  water-courses,  dammed  up,  or  deranged 
by  the  lava  currents,  formed  new  channels,  and  ac- 
cumulated beds  of  gravel,  sand,  and  clay.  Gigantic 
deer  and  oxen  still  inhabited  the  district,  having 
for  contemporaries  hyenas  and  other  carnivora. 
Volcanic  eruptions  succeeded,  and  continued  till  a 
comparatively  recent  period. 

Lastly.  Floods  and  rivers  of  later  date,  which 
now  constitute  the  drainage  of  the  country,  began 
to  wear  away  channels  through  the  beds  of  lava  and 
limestone  to  the  granite  rock  beneath,  intersected 
the  country  with  valleys  and  ravines,  and  spread 
over  the  ancient  beds  the  modern  alluvial  soil.* 

*  This  account  of  the  volcanic  district  of  Auvergne,  is  an 
abstract  of  the  interesting  Essays  of  Messrs.  Bakewell,  Scrope, 


266  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

46.  EROSION  OF  VALLEYS  BY  WATER-CURRENTS. 
— There  is  perhaps  no  district  which  exhibits  in 
more  striking  characters  the  erosive  power  of  run- 
ning water,  than  Auvergne.  In  many  places  the 
basalt  is  columnar,  like  that  of  Staffa,  and  the  Giants' 
Causeway ;  and  one  range,  on  the  banks  of  the 
Ardeche,  forms  a  majestic  colonnade  150  feet  in 
height,  extending  a  mile  and  a  half  along  the  valley 
which  has  been  channelled  out  by  the  stream  that 
flows  at  its  base.  Mr.  Scrope's  description  of  this 
process  is  highly  graphic.  "  The  bed  of  the  Ardeche 
is  strewed  with  basaltic  boulders,  pebbles,  and  sand, 
originating  from  the  destruction  of  the  columnar 
ranges.  In  some  of  the  volcanic  cones  the  beds 
of  basalt  may  be  traced  issuing  from  the  crater  and 
following  the  inequalities  of  the  valley,  just  as  a 
stream  of  lava  would  flow  down  the  same  course  at 
the  present  time.  Yet  these  ancient  currents  have 
since  been  corroded  by  rivers  which  have  worn 
through  a  mass  of  rock  150  feet  in  height,  and 
formed  a  channel  even  in  the  granite  rocks  beneath, 
since  the  lava  first  flowed  into  the  valley.  In  an- 
other spot,  a  bed  of  basalt  160  feet  high,  has  been 
cut  through  by  a  mountain  stream,  and  very  beau- 
tiful columnar  masses  are  displayed.  The  vast  ex- 
cavations effected  by  the  erosive  power  of  water 
along  the  valleys  which  feed  the  Ardeche,  since 

Lyell,  Murchison,  Dr.  Daubeny,  Dr.  Hibbert,  MM.  Croiset, 
Jobert,  Robert,  and  Bertrand-Roux.  Mr.  Scrope's  work  cannot 
be  perused,  even  by  the  general  reader,  without  deep  interest. 


§  47.  EXTINCT  VOLCANOES  OF  THE  RHINE.  267 

their  invasion  by  lava  currents,  prove  that  even  the 
most  recent  of  these  volcanic  eruptions  belong  to 
an  era  incalculably  remote." 

4-7.  EXTINCT  VOLCANOES  OF  THE  RHINE. — 
I  have  dwelt  so  long  on  the  Phlegraean  fields  of 
Auvergne,  that  but  a  brief  space  can  be  afforded 
to  another  group  of  tertiary  volcanoes.  Every  one 
who  has  ascended  the  Rhine,  will  remember  where 

"  The  castled  crag  of  Drachenfels 
Frowns  o'er  the  wide  and  winding  Rhine," 

forming  one  of  the  Siebengebirge,  or  Seven  Moun- 
tains, whose  majestic  and  graceful  forms  suddenly 


TAB.  46.— THE  DRACHENFELS. 
(Drawn  by  Miss  Jane  Allnutt.) 


burst  on  the  sight,  rising  from  the  level  plains  on 
the  right  bank  of  the  river,  to  an  altitude  of  nearly 


268  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

1,500  feet.      These  picturesque  objects  belong  to 
a  group  of  extinct  volcanoes  ;  while,  on  the  opposite 
side  of  the  river,  the  Eifel,  with  its  crater  covered 
with  scoriae  and  cinders,  and  lava  currents  still  dis- 
tinctly visible,  attest  the  wide  area  over  which  those 
ancient  fires  once  extended.      Unlike  the  district 
we  have  just  noticed,  the  foundation  rock  of  the 
country  is  an  ancient  sedimentary  deposit,   called 
greywacke,  consisting  of  coarse  red  sandstone  and 
slate  of  a  peculiar  character,  which  we  shall  describe 
hereafter,  thrown  into  a  highly  inclined  position. 
Through  these  beds  the  volcanic  eruptions,   con- 
sisting of  trachyte,  basalt,  and  other  modifications 
of  trap  rocks  and  scoriae,  have  forced  their  way. 
The  basalt  is  black,  very  compact,  and  breaks  into 
sharp  fragments  ;    it  is  frequently  columnar,  and 
the  separate  hexagonal  pillars  are  made  use  of  for 
posts  and  paving,  in  the  adjacent  towns.      Such, 
says  Mr.  Homer  (whose  interesting  memoir*  has 
furnished  the  materials  for  this  imperfect  sketch), 
is  the  profusion  of  basaltic  pillars,  that  the  walls 
of  the  town  of  Linz  are  wholly  built  of  these  mate- 
rials, placed  on  their  sides,  with  the  ends  projecting 
outwards.     The  streets  are  paved  with  the  smaller 
columns  set  on  end,  thus  forming  a  miniature  re- 
presentation of  the  Giants'  Causeway;  and  the  same 
volcanic  product  forms  a  large  proportion  of  the 
walls  of  Bonn  and  Cologne.      The  greywacke  is 

*  On  the  Geology  of  the  Environs  of  Bonn,  by  Leonard 
Homer,  Esq.  F.R.S.     Geological  Transactions,  vol.  iv.  1836. 


§  48.  BROWN  COAL  FORMATION.  269 

covered  by  a  series  of  tertiary  deposits,  consisting 
of  sand,  sandstone,  clay,  and  lignite,  constituting 
what  is  termed  a  brown  coal  formation.  On  these 
strata  an  extensive  layer  of  gravel  is  superposed, 
over  which  is  spread  a  loosely  coherent,  sandy  loam, 
provincially  termed  loess,  which  contains  recent 
species  of  terrestrial  and  fresh-water  shells,  and 
forms  the  subsoil  of  the  vast  plains  in  which  Bonn 
and  Coblentz  are  situated,  extending  as  far  as  the 
falls  of  Schaifhausen. 

4-8.  BROWN  COAL  FORMATION. — As  the  usual 
condition  in  which  bituminized  vegetable  matter 
occurs  in  the  tertiary  formations,  is  well  exemplified 
in  the  brown  coal,  or  lignite,  of  the  Rhine,  it  will 
be  instructive  to  examine  the  characters  of  this 
deposit  somewhat  in  detail;  for  we  shall  thereby 
obtain  data  which  will  prepare  us  for  the  investi- 
gation of  the  ancient  carboniferous  system.  This 
formation,  which  is  spread  over  a  great  extent  of 
country  on  both  sides  of  the  Rhine,  consists  of 
clay,  sand,  sandstone,  conglomerates,  clay  and  iron- 
stone, and  lignite,  or  bituminized  wood  of  various 
qualities,  disposed  in  distinct  beds,  and  intermixed 
with  argillaceous  matter.  The  breadth  of  the 
ridge  of  low  hills  formed  by  this  assemblage  of 
strata  on  the  left  bank  of  the  Rhine,  is  from  three 
to  five  miles,  its  elevation  varying  from  50  to 
200  feet. 

The  lignite  occurs  in  the  following  states:  — 
1.  A  black  earthy  and  pulverulent  substance.  2.  Con- 


270  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

cretionary  masses,  with  leaves  and  fragments  of 
wood.  3.  Wood  in  various  degrees  of  bitumini- 
zation,  and  of  shades  of  colour,  from  a  light-brown 
to  jet-black.  4.  Very  finely  laminated  masses  of 
bituminous  matter  and  clay,  of  a  dark  chocolate 
colour,  and  separating  into  elastic  flakes,  as  thin  as 
paper,  whence  its  name  papierkohle.  These  speci- 
mens, collected  by  Sir  P.  M.  de  Grey  Egerton,  Bart, 
exhibit  the  peculiar  character  of  the  substance, 
which  is  so  highly  bituminous  as  to  burn  with  a 
bright  flame.  The  wood  is  generally  in  inconsider- 
able fragments ;  but  stems  of  large  trees,  somewhat 
compressed,  occasionally  occur ;  in  some  instances 
the  trees  are  imbedded  in  an  upright  position,  with 
the  roots  attached  and  the  stems  passing  through 
several  beds  of  lignite.  In  many  examples  the  wood 
is  so  little  changed,  that,  like  the  timber  of  our 
peat-bogs,  it  is  employed  in  building ;  in  others  it 
is  highly  pyritous,  or  in  other  words,  is  impregnated 
with  sulphuret  of  iron,  like  the  fossil  vegetables 
of  Sheppey.  Mr.  Homer  states,  as  the  result  of  his 
investigations,  that  there  were  extensive  fresh- water 
lakes,  in  the  sediments  of  which  trees  and  plants, 
drifted  by  land-floods,  were  engulfed ;  and  that  vol- 
canic eruptions  were  simultaneously  going  on,  in 
the  same  manner  as  in  the  modern  submarine 
volcanoes.  There  is  a  great  fault,  or  dislocation, 
of  the  brown  coal  formation,  which  may  be  attri- 
buted to  a  powerful  and  sudden  volcanic  explosion, 
that  probably  occasioned  the  elevation  of  the 


§48.  BROWN  COAL  FORMATION.  271 

Siebengebirge,  and  raised  up  that  portion  of  the 
coal-beds  which  reposes  on  the  flanks  of  those 
peaks.  The  gravel  covering  the  lignite,  must  have 
been  strewed  over  the  plain  previously  to  this  ele- 
vation, for  it  is  found  on  both  sides  of  the  river  at 
a  great  height,  and  not  in  the  intermediate  plain. 
These  inductions  are  so  evident  as  to  require  no 
comment. 

The  ancient  alluvium,  the  loess,  very  much  re- 
sembles a  bed  of  loam  which  occurs  in  some  parts 
of  Lewes  Levels,  and  incloses  fresh-water  and  land 
shells  of  many  existing  species ;  it  rarely  contains 
bones  of  quadrupeds ;  a  few  remains  of  the  horse 
and  mammoth  have  however  been  discovered.* 
From  the  extensive  distribution  of  this  deposit,  and 
its  occurrence  at  various  elevations,  in  some  in- 
stances on  the  flanks  of  mountains  1,200  feet  above 
the  level  of  the  sea,  at  others  spread  out  over  the 
gravel  of  the  vast  plain  of  the  Rhine,  it  is  inferred, 
that  although  the  loess  has  been  deposited  since 
the  existing  system  of  the  hills  and  valleys  of  the 
country,  yet  that  changes  must  have  taken  place  in 
the  physical  geography  of  the  district,  subsequent 
to  its  original  formation ;  and  there  is  reason  to 
conclude,  that  since  the  deposition  of  this  fluviatile 
loam  all  the  land  between  Switzerland  and  Holland 
has  suffered  a  subsidence,  and  a  subsequent  eleva- 
tion, to  the  amount  of  many  hundred  feet.f 

*  Principles  of  Geology,  vol.  iv.  p.  33. 

f  Ibid. ;  read  with  particular  attention,  pp.  36  and  37. 


272  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

49.  OTHER  TERTIARY  STRATA  OF  EUROPE, 
NORTH  AMERICA,  &c. — It  has  already  been  men- 
tioned that  strata,  referable  to  the  period  compre- 
hended between  the  newest  secondary  formations 
and  the  human  epoch,  occur  throughout  Europe, 
presenting  in  some  instances  well-defined  groups, 
with  marked  boundaries ;  in  others,  vast  areas,  over 
which  these  deposits  are  irregularly  spread.  The 
geographical  relations  of  the  tertiary  strata  to  the 
existing  lands  and  seas,  is  an  interesting  subject  of 
inquiry,  but  one  on  which  my  limits  forbid  me  to 
enter.  I  may  however  observe,  that  Europe  must 
have  possessed  many  of  its  most  striking  physical 
characters  at  the  commencement  of  the  eocene 
period ;  and  that  its  present  configuration  has  been 
produced  by  the  conjoint  effect  of  successive  muta- 
tions in  the  relative  level  of  land  and  water,  during 
the  deposition  of  the  marine  and  fresh- water  strata, 
reviewed  in  this  discourse.  In  India,  formations  of 
a  like  nature  have  been  observed  in  the  Burmese 
empire,  in  the  Sub-Himalaya  mountains,  and  in  the 
Caribari  hills ;  and  among  the  remains  of  various 
quadrupeds  a  new  species  of  anthracotherium,  one 
of  the  genera  discovered  in  the  tertiary  strata  of 
France,  has  been  found. 

In  North  America  the  researches  of  Dr.  Morton, 
Professor  Vanuxem,  and  other  observers,  have 
shown  that  in  the  territories  of  the  United  Slates 
tertiary  deposits  extend  over  a  great  part  of  Mary- 
land, along  the  coast  of  New  York  and  New 


§  50.  TERTIARY  STRATA  OF  THE  ANDES.  273 

England,  and  occur  in  New  Jersey,  Delaware,  Long 
Island,  &c.  The  tertiary  beds  of  Maryland  consist 
of  limestone,  clay,  sand,  and  gravel,  and  abound 
in  the  usual  types  of  European  tertiary  marine 
shells.  1  have  placed  before  you  an  extensive 
collection  from  the  United  States,  for  which  I  am 
indebted  to  the  kindness  of  Dr.  Morton,  Mr.  Conrad, 
Professor  Silliraan,  Dr.  Harlan,  and  other  American 
savans ;  and  you  will  observe  how  striking  is  the 
general  analogy  between  these  shells  and  those  of 
the  Paris  and  London  basins.  The  turritella^  vene- 
ricardia,  fusus,  ancilla,  &c.  are  identical  with  the 
European  species ;  but  some  of  the  types  are  alto- 
gether new. 

50.  ALTERED  TERTIARY  STRATA  OF  THE  ANDES. 
— But  striking  as  are  the  proofs  already  adduced 
of  elevation,  and  other  effects  of  volcanic  agency 
during  the  tertiary  period,  these  sink  into  com- 
parative insignificance  when  contrasted  with  the 
enormous  changes  which  have  taken  place  in  the 
great  mountain  chains  of  South  America  during 
the  same  geological  epoch.  From  the  researches  of 
an  eminent  naturalist  and  highly  intelligent  ob- 
server, Mr.  Charles  Darwin,  we  learn  that  an 
extensive  tertiary  system,  analogous  to  that  of 
Europe,  skirts  both  flanks  of  the  primary  rocks 
which  form  the  southern  chain  of  the  Andes,  the 
latter  having  suffered  a  certain  degree  of  elevation 
before  the  deposition  of  the  former.  These  strata 
are  of  great  thickness  and  extent,  and  separable 


274  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

into  two  groups  ;  the  lowermost  beds,  like  those  of 
Auvergne,  repeatedly  alternate  with  lavas,  and  thus 
denote  the  commencement  of  the  eruptions  of  the 
ancient  craters.  Over  these  are  accumulations  of 
porphyritic  pebbles,  covered,  at  elevations  of  many 
hundred  feet,  by  beds  of  shells  of  recent  species  ; 
and  the  sides  of  the  mountains  appear  like  a  suc- 
cession of  sea-beaches,  which  have  been  slowly  and 
tranquilly  lifted  up.  The  altered  character  of  the 
tertiary  deposits  within  the  influence  of  the  igneous 
products, — the  transmutation  of  accumulations  of 
loose  pebbles  into  solid,  compact  rocks, — and  the 
occurrence  of  metalliferous  veins  in  strata  of  com- 
paratively modern  formation, — are  facts  so  powerfully 
exemplifying  the  geological  principles  enunciated 
in  the  former  lectures,  that  although  this  discourse 
has  extended  to  a  great  length,  I  cannot  omit  Mr. 
Darwin's  spirited  and  graphic  description  of  these 
phenomena,  as  originally  communicated  in  a  letter 
to  Professor  Henslow,  of  Cambridge,  dated  Valpa- 
raiso, March  1835. 

"  You  will  have  heard  of  the  dreadful  earthquake  of  the  20th 
February.  I  wish  some  of  the  geologists,  who  think  the  earth- 
quakes of  these  times  are  trifling,  could  see  how  the  solid  rocks 
are  shivered.  In  the  town  there  is  not  one  house  habitable  ; 
the  ruins  remind  me  of  the  drawings  of  the  desolated  eastern 
cities.  We  were  at  Valdivia  at  the  time,  and  felt  the  shock  very 
severely.  The  sensation  was  like  that  of  skating  over  very  thin 
ice,  that  is,  distinct  undulations  were  perceptible.  The  whole 
scene  of  Conception  and  Talesana  is  one  of  the  most  interesting 
spectacles  we  have  beheld  since  we  left  England.  I  was  much 
pleased  at  Chiloe  by  finding  a  thick  bed  of  recent  oyster-shells 


§  50.  TERTIARY  STRATA  OF  THE  ANDES.  273 

capping  the  tertiary  plain,  out  of  which  grew  large  forest  trees. 
I  can  prove  that  both  sides  of  the  Andes  have  risen  in  this 
recent  period  to  a  considerable  height.  Here  the  shells  were 
350  feet  above  the  sea.  On  the  bare  sides  of  the  Cordilleras 
complicated  dykes  and  wedges  of  variously  coloured  rocks  are 
seen  traversing,  in  every  possible  form  and  shape,  the  same  for- 
mation, and  thus  proving  by  their  intersections  a  succession  of 
violences.  The  stratification  in  all  the  mountains  is  beautifully 
distinct,  and  owing  to  a  variety  of  colouring  can  be  seen  at 
great  distances.  Porphyritic  conglomerates,  resting  on  granite, 
form  the  principal  masses.  I  cannot  imagine  any  part  of  the 
world  presenting  a  more  extraordinary  scene  of  the  breaking  up 
of  the  crust  of  the  globe  than  these  central  peaks  of  the  Andes. 
The  strata  in  the  highest  pinnacles  are  almost  universally  in- 
clined at  an  angle  from  70°  to  80°.  I  cannot  tell  you  how  much 
I  enjoyed  some  of  the  views ;  it  is  alone  worth  coming  from 
England  to  feel  at  once  such  intense  delight.  At  an  elevation 
of  from  ten  to  twelve  thousand  feet  there  is  a  transparency  in  the 
air,  and  a  confusion  of  distances,  and  a  stillness,  which  give  the 
sensation  of  being  in  another  world.  The  most  important  and 
most  developed  formation  in  Chili  is  the  porphyritic  concrete. 
From  a  great  number  of  sections  I  find  it  to  be  a  true  coarse 
conglomerate  or  breccia,  which  passes  by  every  step  in  slow 
gradation  to  a  fine  clay-stone  porphyry  ;  the  pebbles  and  cement 
becoming  porphyritic,  till  at  last  all  is  blended  in  one  compact  rock. 
The  porphyries  are  excessively  abundant  in  this  chain,  and  at 
least  four-fifths  of  them,  I  am  sure,  have  been  thus  produced  from 
sedimentary  beds  in  situ.  The  Uspellata  range  is  geologicallly 
although  only  six  or  seven  thousand  feet  high,  a  continuation  of 
the  grand  eastern  chain.  It  has  its  nucleus  of  granite,  consist- 
ing of  beds  of  various  crystalline  rocks,  (which  I  have  no  doubt 
are  subaqueous  lavas,)  alternating  with  sandstone,  conglome- 
rates, and  white  aluminous  beds,  like  decomposed  felspar, 
with  many  other  curious  varieties  of  sedimentary  deposits.  In 
an  escarpment  of  compact  greenish  sandstone,  /  found  a  small 
wood  of  petrified  trees  in  a  vertical  position,  or  rather  the  strata 
were  inclined  about  20°  or  30°  to  one  point  of  the  trees,  and  70°  to 
T2 


276  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

the  other ;  that  is,  before  the  tilt,  they  were  truly  vertical.  The 
sandstone  consists  of  many  horizontal  layers.  Eleven  of  the 
trees  are  perfectly  silicified,  and  resemble  the  dicotyledonous 
wood  which  I  found  at  Chiloe  and  Conception ;  the  others,  from 
thirty  to  forty  in  number,  I  only  know  to  be  trees  from  the 
analogy  of  form  and  position  ;  they  consist  of  snow-white 
columns  of  coarsely  crystallized  carbonate  of  lime.  The  largest 
trunk  is  seven  feet  in  circumference.  They  are  all  close  toge- 
ther, within  one  hundred  yards,  and  about  the  same  level ;  no 
where  else  could  I  find  any.  It  cannot  be  doubted  that  the 
layers  of  fine  sandstone  have  quietly  been  deposited  between  a 
clump  of  trees,  which  were  fixed  by  their  roots.  The  sandstone 
rests  on  lava  ;  is  covered  by  a  great  bed,  apparently  about  one 
thousand  feet  thick,  of  black  augite  lava  ;  and  over  this  there  are  at 
least  five  grand  alternations  of  such  rocks,  and  aqueous  sedimentary 
deposits,  amounting  in  thickness  to  several  thousand  feet.  Accord- 
ing to  my  view  of  these  phenomena,  the  granite,  which  forms 
peaks  of  a  height  probably  of  14,000  feet,  has  been  fluid  in  the 
tertiary  epoch ;  strata  of  that  period  have  been  altered  by  its 
heat,  and  are  traversed  by  dykes  from  the  mass,  and  are  now 
inclined  at  high  angles,  and  form  regular  or  complicated  anti- 
clinal lines.  To  complete  the  climax,  these  same  sedimentary  strata 
and  lavas  are  traversed  by  very  numerous  true  metallic  veins  of 
iron,  copper,  arsenic,  silver,  and  gold,  and  these  can  be  traced  to 
the  underlying  granite.  A  gold  mine  has  been  worked  close  to  the 
clump  of  silicified  trees !" 

51.  TERTIARY  SALIFEROUS  DEPOSIT. — Not  only 
coal,  but  even  extensive  beds  of  rock  salt  occur  in 
the  tertiary  system.  The  celebrated  salt  mines  of 
Gallicia,  of  which  M.  Bou6*  has  given  an  inte- 
resting description,  belong  to  this  epoch.  The 
deposit  is  nearly  3000  yards  long,  1066  broad,  and 
280  yards  deep.  The  upper  part  of  the  mine 

*  Journal  de  Geologic. 


§52.  RETROSPECT.  277 

consists  of  green  salt,  with  nodules  of  gypsum  in 
marl.  The  salt  contains  in  some  places  lignite, 
bituminous  wood,  and  shells.  In  the  lower  division 
are  beds  of  arenaceous  marls,  with  lignite,  impres- 
sions of  plants,  and  veins  of  salt ;  coarse  sandstone, 
with  vegetable  remains ;  aluminous  and  gypseous 
shale,  and  indurated  calcareous  marl,  with  sulphur, 
salt,  and  gypsum. 

52.  RETROSPECT. — So  numerous  and  varied  have 
been  the  phenomena  presented  to  our  notice,  that 
a  comprehensive  retrospect  is  necessary,  in  order 
that  we  may  obtain  a  correct  idea  of  the  important 
and  highly  interesting  deductions  resulting  from 
this  general  survey  of  the  tertiary  formations. 

In  the  pliocene,  or  newer  tertiary,  which  also 
embraces  the  mammalian  epoch  of  the  last  lecture, 
the  fossil  remains  in  the  alluvial  deposits  afford  in- 
contestible  proof  that  the  mammoth,  mastodon,  hip- 
popotamus, dinotherium,  and  other  colossal  animals 
of  extinct  species  and  genera,  together  with  birds, 
reptiles,  and  enormous  carnivora,  inhabited  such 
districts  of  our  continents  as  were  then  dry  land ; 
while  the  older  tertiary,  or  eocene,  incloses  the  bones 
of  land  animals,  principally  of  a  lacustrine  character, 
which  approximate  to  certain  races  that  now  exist 
in  the  torrid  zone,  but  belong  to  extinct  genera, 
that  preceded  the  mammoth  and  the  mastodon. 
The  seas  and  lakes  of  that  remote  epoch  occupied 
areas  which  are  now  above  the  waters ;  and  rocks 
and  mountains,  hills  and  valleys,  streams  and  rivers, 


278  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

diversified  the  surface  of  countries  which  are  now 
destroyed  or  entirely  changed  ;  and  whose  past  ex- 
istence is  revealed  by  the  spoils  which  the  streams 
and  rivers  have  accumulated  in  the  ancient  lakes 
and  deltas.  The  ocean  abounded  in  mollusca,  crus- 
tacea,  and  fishes,  a  large  proportion  of  which  is 
referable  to  extinct  species.  Crocodiles,  turtles, 
birds,  and  insects,  were  contemporary  with  the 
palaeotherium,  and  anthracotherium ;  and  animal 
organization,  however  varied  in  certain  types,  pre- 
sented the  same  general  outline  as  in  modern 
times  ;  the  extinction  of  species  and  genera  being 
then,  as  now,  in  constant  activity.  The  vegetable 
world  also  contained  the  same  great  divisions ;  there 
were  forests  of  oak,  elm,  and  beech ;  of  firs,  pines, 
and  other  coniferous  trees;  palms,  tree-ferns,  and 
the  principal  groups  of  modern  floras  ;  while  the 
water,  both  salt  and  fresh,  teemed  with  the  few 
and  simple  forms  of  vegetable  structure  peculiar 
to  that  element.  The  state  of  the  inorganic  world 
is  not  less  manifest :  the  abrasion  of  the  land  by 
streams  and  rivers, — the  destruction  of  the  sea- 
shores by  the  waves,  and  the  formation  of  beach 
and  shingle, — the  desolation  inflicted  by  volcanic 
eruptions, — all  these  operations  were  then,  as  now, 
in  constant  action.  The  bed  of  an  ancient  sea,  con- 
taining myriads  of  the  remains  of  fishes,  Crustacea, 
and  shells,  now  forms  the  site  of  the  capital  of 
Great  Britain  ;  and  accumulations  of  tropical  fruits 
and  plants,  drifted  by  ancient  currents  from  other 


§  ,;2.  RETROSPECT.  279 

climes,  constitute  islands  in  the  estuary  of  the 
Thames ;  while  the  sediments  of  lakes  and  gulfs, 
teeming  with  the  skeletons  of  .beings  which  are 
blotted  out  from  the  face  of  the  earth,  compose  the 
soil  of  the  metropolis  of  France. 

Although  the  changes  in  the  relative  level  of  the 
land  and  sea  during  this  epoch  were  numerous  and 
extensive,  yet  one  region  still  preserves  traces  of 
its  original  physical  geography  ;  and  although  the 
earthquake  has  rent  its  mountains  to  their  very 
centre — though  hundreds  of  volcanoes  have  again 
and  again  spread  desolation  over  the  land — and 
inundations  and  mountain  torrents  have  excavated 
valleys,  and  chequered  the  plains  with  ravines  and 
water-courses — yet  the  grand  primeval  features  of 
that  country  remain  ;  and  we  can  trace  the  boun- 
daries of  its  ancient  lakes,  and  the  succession  of 
changes  it  has  undergone  from  the  first  outbreak  of 
its  volcanoes,  to  the  commencement  of  the  present 
state  of  repose.  The  lowermost  lacustrine  deposits 
in  Auvergne,  which  are  spread  over  the  foundation 
rock  of  granite  unmixed  with  igneous  productions, 
mark  the  period  antecedent  to  the  volcanic  era  ; 
while  the  intrusions  of  lava  and  scoriae  in  the  super- 
incumbent strata,  denote  the  first  eruptions  of  Mont 
Dome.  The  succeeding  period  of  tranquillity  is 
recorded  in  characters  alike  intelligible.  The  slow 
deposition  of  calcareous  mud — the  incrustation  of 
successive  generations  of  aquatic  insects,  Crustacea, 
and  mollusca,  and  we  may  even  add  of  infusoria — 


280  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

the  imbedding  of  the  bones  of  mammalia,  birds,  and 
reptiles — the  accumulation  of  lignite  and  other  vege- 
table matter — are  data  from  which  we  may  restore 
the  ancient  country  of  Central  France. 

It  was  a  region  encircled  by  a  chain  of  granite 
mountains,  watered  by  numerous  streams  and  rivu- 
letSj  and  possessing  lakes  of  vast  extent.  Its  soil 
was  covered  with  luxuriant  vegetation,  and  peopled 
by  palseotheria,  anoplotheria,  and  other  terrestrial 
mammalia ;  the  crocodile  and  turtle  found  shelter 
in  its  marshes  and  rivers  ;  aquatic  birds  frequented 
its  fens,  and  sported  over  the  surface  of  its  lakes ; 
while  myriads  of  insects  swarmed  in  the  air,  and 
passed  through  their  wonderful  metamorphoses  in 
the  waters.  In  a  neighbouring  region,*  herds  of 
ruminants  and  other  herbivora,  of  species  and 
genera  now  no  more,  with  birds  and  reptiles,  were 
the  undisturbed  occupants  of  a  country  abounding 
in  palms  and  tree-ferns,  and  having  rivers  and  lakes, 
with  gulfs  which  teemed  with  the  inhabitants  of  the 
sea;  and  to  this  district  the  fiery  torrents  of  the 
volcano  did  not  extend.  But  to  return  to  Auvergne 
— a  change  came  over  the  scene — violent  eruptions 
burst  forth  from  craters  long  silent — the  whole 
country  was  laid  desolate — its  living  population 
was  swept  away — all  was  one  vast  waste,  and  steri- 
lity succeeded  to  the  former  luxuriance  of  life  and 
beauty.  Ages  rolled  by — the  mists  of  the  mountains 
and  the  rains,  produced  new  springs,  torrents,  and 
*  The  Paris  basin  is  about  220  miles  from  Auvergne. 


. 


§52.  RETROSPECT.  281 

rivers — a  fertile  soil  gradually  accumulated  over 
the  cooled  lava  currents  and  the  beds  of  scoriae, 
to  which  the  sediments  of  the  ancient  lakes,  borne 
down  by  the  streams,  largely  contributed.  Another 
vegetation  sprang  up — the  mammoth  and  mastodon, 
with  enormous  deer  and  oxen,  now  quietly  browsed 
in  the  verdant  plains — other  changes  succeeded — 
those  colossal  forms  of  life  in  their  turn  passed 
away,  and  at  length  the  earlier  races  of  mankind 
took  possession  of  a  country,  which  had  once  more 
become  a  scene  of  fertility  and  repose. 

To  those  who  have  favoured  me  with  their  atten- 
tion through  these  discourses,  it  cannot  be  necessary 
to  insist  that  the  changes  in  organic  and  inanimate 
nature,  which  I  have  thus  rapidly  portrayed,  are 
supported  by  proofs  so  incontrovertible,  and  traced 
in  language  so  intelligible,  as  to  constitute  a  body 
of  evidence  with  which  no  human  testimony  can 
compete.  It  is  true  that  the  time  required  for  this 
succession  of  events  must  have  extended  over  an 
immense  period;  but,  as  I  have  before  remarked, 
time  and  change  are  great  only  in  relation  to  the 
beings  which  note  them,  and  every  step  we  take  in 
geology  shows  the  folly  and  presumption  of  attempt- 
ing to  measure  the  operations  of  nature  by  our  own 
brief  span.  "  There  are  no  minds,"  says  Mr.  Scrope, 
"  that  would  for  one  moment  doubt  that  the  God  of 
Nature  has  existed  from  all  eternity  ;  but  there  are 
many  who  would  reject  as  preposterous,  the  idea 
of  tracing  back  the  history  of  His  works  a  million 


282  THE  WONDERS  OF  GEOLOGY.  LKCT.  III. 

of  years.     Yet  what  is  a  million,  or  a  million  of 
millions  of  years,  when  compared  to  eternity  ?  "  * 

Germany  presents  us  with  an  interesting  series 
of  analogous  changes,  effected  in  a  later  era.  The 
outburst  of  the  now  extinct  volcanoes  of  the  Rhine, 
the  accumulation  of  fluviatile  silt  over  the  plains, 
and  the  subsequent  elevation  of  the  whole  country, 
show  that  these  physical  mutations  were  not  con- 
fined to  a  single  region  or  period. 

In  the  Andes,  the  enormous  disruptions  and 
elevations  of  the  most  ancient  as  well  as  modern 
deposits,  teach  us,  that  through  a  long  lapse  of 
ages,  the  volcanic  fires  of  South  America  have  acted 
with  intense  energy;  and  yet  more,  that  the  melting 
and  transmutation  of  loose  materials  into  compact 
rocks,  the  conversion  of  incoherent  strata  into  solid 
stone,  and  even  the  sublimation  of  gold  and  other 
metals  into  fissures  and  veins,  are  phenomena  which 
have  taken  place  since  our  seas  were  peopled  by 
mollusca  of  existing  species.  The  importance  of 
these  extraordinary  and  interesting  facts  will  be 
rendered  more  obvious  in  a  subsequent  lecture. 

53.  CONCLUDING  REMARKS. — In  conclusion,  it 
will  be  useful  to  inquire,  even  though  some  repe- 
tition may  be  incurred,  what  are  the  legitimate 
inferences  from  the  facts  that  have  been  placed 
before  us,  as  to  the  condition  of  the  earth  and  its 
inhabitants  during  the  tertiary  epoch?  Was  there, 
as  some  have  supposed,  an  essential  difference  in 
*  Geology  of  Central  France. 


§  53.  CONCLUDING  REMARKS.  283 

the  constitution  of  the  earth? — was  its  surface  more 
covered  with  lakes  and  marshes  than  now? — and 
did  animal  life  more  abound  in  those  types,  which 
are  suitable  to  a  lacustrine  condition?  —  or  have 
such  conclusions  been  drawn  from  a  partial  view  of 
the  phenomena,  and  do  the  facts  only  warrant  the 
inference  that  certain  regions  which  are  now  dry 
land  were  in  ancient  times  occupied  by  vast  lakes, 
and  that  there  may  have  existed  contemporaneously 
as  great  an  extent  of  dry  land  as  at  present,  in  areas 
now  buried  beneath  the  ocean  ?  In  the  fossilized 
remains  of  the  tertiary  population  of  the  land  and 
waters,  we  find  all  the  grand  types  of  the  existing 
animal  creation — terrestrial,  lacustrine,  and  marine 
mammalia  —  herbivora,  carnivora,  birds  of  every 
order,  and  of  numerous  species  and  genera — rep- 
tiles, fishes,  Crustacea,  insects,  zoophytes,  and  even 
those  living  atoms,  the  infusoria* — in  short,  all  the 
leading  divisions,  and  even  sub-divisions  of  animal 
existence.  In  the  vegetable  world,  as  I  have  already 
remarked,  the  same  general  analogy  is  maintained. 
And  as  all  these  varied  forms  of  being  required 
physical  conditions  suitable  to  their  respective  or- 
ganizations, we  have  at  once  conclusive  evidence 
that  the  general  constitution  of  the  earth,  during 
the  tertiary  epoch,  could  not  have  essentially  differed 
from  the  present.  Dry  land  and  water,  continents 

*  In  tertiary  strata  the  remains  of  beings  of  which  thousands 
of  millions  would  occupy  but  a  cubic  inch  have  been  discovered. 
They  will  be  described  hereafter. 


284  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

and  islands,  existed  then,  as  now, — their  geogra- 
phical distribution  may  have  varied,  —  the  tem- 
perature in  certain  latitudes  may  have  been  much 
higher, — countries  may  have  existed  in  areas  now 
covered  by  water,  and  marshes  and  fens  have  pre- 
vailed in  regions  now  arid  and  waste ;  but  the  same 
agents  of  destruction  and  of  renovation  were  then, 
as  now,  in  constant  activity.  It  is  true  that  immense 
numbers  of  large  mammalia  lie  buried  in  regions 
where  it  is  utterly  impossible  such  creatures  could 
now  find  subsistence,  and  in  latitudes  whose  climates 
are  unsuitable  to  such  forms  of  organization.  But 
some  of  these  apparent  anomalies  may  be  explained 
by  the  fact,  that  the  alluvial  beds  in  which  these 
remains  occur  cannot  have  been  the  sites  of  the  dry 
land  on  which  these  lost  beings  existed;  they  are 
the  sediments  of  ancient  lakes — the  deltas  of  former 
rivers — the  estuaries  of  seas — they  are  formed  of 
the  detritus  of  the  land  transported  from  a  distance. 
If  the  Gulf-stream  annually  strews  the  shores  of  the 
Hebrides  with  the  fruits  of  torrid  climes,  the  currents 
of  the  ancient  seas  must  have  produced  analogous 
results;  and  in  our  attempt  to  interpret  past  changes, 
it  must  not  be  forgotten  that  they  have  most  pro- 
bably been  produced  by  causes  similar  to  those 
which  are  still  in  action.  I  do  not  question  the 
assumption  that  the  countries  containing  these  fossil 
remains  may  have  enjoyed  a  milder  climate  during 
the  tertiary  epoch  than  at  present ;  or  that  in  still 
more  ancient  periods  there  may  not  have  prevailed 


§  53.  CONCLUDING  REMARKS.  285 

all  over  the  world  a  much  higher  temperature  than 
now,  dependent  on  the  internal  condition  of  our 
planet.  But  it  appears  to  me  that  the  variation  of 
climate  which  a  change  in  the  distribution  of  the 
land  and  water  would  occasion,  as  suggested  by 
Mr.  Lyell,* — and  a  difference  in  the  radiation  of 
heat  from  internal  sources,  as  explained  by  Sir 
J.  Herschel  and  Mr.  Babbage  (page  97), — may  ac- 
count for  the  phenomena  which  our  examination  of 
the  tertiary  formation  has  revealed. 

The  occurrence  of  groups  of  animals  of  the  same 
families,  in  certain  districts,  is  in  strict  conformity 
with  the  distribution  of  living  species,  in  regions 
not  under  the  control  of  man.  Thus  when  ancient 
France  presented  a  system  of  lakes,  animals  fitted 
for  such  physical  conditions  found  there  the  means 
of  subsistence — when  the  vast  plains  and  forests  of 
America  were  adapted  for  colossal  mammalia,  there 
the  mastodon  and  the  mammoth  obtained  food  and 
shelter — and  when  the  former  continent  of  Europe 
swarmed  with  herbivora,  the  carnivorous  tribes,  as 
the  lion  and  the  tiger,  the  bear  and  the  hyena,  ob- 
tained the  support  which  their  habits  and  economy 
required. 

One  striking  feature  in  the  events  that  have 
passed  in  review  before  us,  is  the  immense  scale  on 
which  the  extinction  of  species  and  genera  has  been 
effected  :  but  it  must  be  remembered  that  our 
observations  have  extended  over  a  period  of  vast 
*  Principles  of  Geology,  vol.  i.  chap.  vii. 


286  THE  WONDERS  OF  GEOLOGY.  LECT.  III. 

duration,  and  that  we  therefore  have  seen  the 
aggregate  effects  of  a  law,  which  even  before  our 
eyes  is  producing  great  and  important  modifications 
in  the  system  of  animated  nature. 

Thus  the  tertiary  epoch  displays  to  us  a  state  of 
the  globe  replete  with  life  and  happiness :  the  phy- 
sical constitution  of  the  earth's  surface  being  then, 
as  now,  admirably  adapted  to  the  habits  and  economy 
of  the  beings  it  was  designed  to  support.     In  the 
most  ancient  periods,  forms  of  life  prevailed  which 
gradually  became  extinct,  and  were  succeeded  by 
others  which  in  their  turn  also  passed  away ;    and 
if  we  trace  the  varying  types  of  being  from  the 
earliest  ages,  we  perceive  a  gradual  approach  to 
the   present   condition  of  organic  existence ;    the 
grand  line  of  separation  between  the  present  and 
the  past  being  the   creation  of  the  human  race. 
From  that  period,  in  proportion  as  man  has   ex- 
tended his  dominion  over  the  earth,  many  races  of 
animals  have  been  either  exterminated,  or  modified 
by  his  caprices  or  necessities ;    and  it  cannot  be 
doubted,  that  in  the  lapse  of  a  few  thousand  years, 
a  total  change  will  have  been  effected  by  human 
agency  alone,  in  the  geographical  distribution  and 
in  the  relative  numerical  proportion  of  the  existing 
genera  and  species. 


LECTURE   IV. 

1.  Introductory  remarks.  2.  Secondary  formations.  3.  The  chalk  for- 
mation. 4.  Chalk  and  flint.  5.  Flint  nodules.  6.  Organic  remains 
in  flint.  7.  Sulphuret  of  iron.  8.  Maastricht  beds.  9.  St.  Peters 
mountain.  10.  Mosaesaurus  of  Maastricht.  11.  Lower  group  of  the 
chalk.  12.  Organic  remains  of  the  chalk.  13.  Fossil  vegetables. 
14.  Fossil  zoophytes.  15.  Radiaria  and  crinoidea.  16.  Echinites. 
17.  Shells  of  the  chalk.  18.  Cephalopoda.  19.  The  belemnite.  20. 
The  nautilus.  21.  The  ammonite,  or  cornu  ammonis.  22.  Turrilite, 
hamite,  &c.  23.  Spirolinites.  24.  Infusoria  in  flint.  25.  Crustacea 
of  the  chalk.  26.  Fishes  of  the  chalk— sharks.  27.  Fossil  salmon, 
or  smelt.  28.  Macropoma,  and  other  fishes  of  the  chalk.  29.  Reptiles 
of  the  chalk.  30.  Review  of  the  chalk  formation.  31.  Geology  of  the 
south-east  of  England.  32.  Geological  phenomena  between  London 
and  Brighton.  33.  The  wealden.  34.  Wealden  of  the  Sussex  coast. 
35.  Pounceford.  36.  Sub-division,  and  extent  of  the  wealden.  37. 
Quarries  of  Tilgate  forest.  38.  Rippled  sandstone.  39.  Wealden  of 
the  Isle  of  Wight.  40.  Isle  of  Purbeck.  41.  Petrified  forest  of  the 
Isle  of  Portland.  42.  Modern  submerged  forest.  43.  Fossils  of  the 
wealden.  44.  Fossil  vegetables — ferns.  45.  Clathraria  and  endo- 
genites.  46.  Seed-vessels.  47.  Fossil  shells.  48.  Sussex  marble. 
49.  Fossil  cypris.  50.  Fishes.  51.  Reptiles  of  Tilgate  forest.  52. 
Fossil  turtles.  53.  Fossil  crocodiles.  54.  The  Swanage  crocodile. 
55.  The  plesiosaurus.  56.  The  megalosaurus.  57.  The  iguanodon. 
58.  The  Maidstone  iguanodon.  59.  Size  of  the  iguanodon.  60.  The 
hylaeosaurus.  61.  Flying  reptiles.  62.  Fossil  birds.  63.  The  country 
of  the  iguanodon.  64.  Sequence  of  geological  changes.  65.  Retro- 
spect of  geological  mutations. 

1.  INTRODUCTORY  REMARKS. — The  knowledge  we 
have  acquired  from  our  investigation  of  the  pheno- 
mena described  in  the  previous  lectures,  will  mate- 
rially facilitate  our  geological  progress,  by  enabling 


288  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

us  to  comprehend  the  former  effects  of  those 
agencies,  by  which  the  surface  of  the  earth  has 
been  renovated  and  maintained. 

The  elevation  of  the  beds  of  seas  and  rivers,  and 
their  conversion  into  fertile  countries — the  submer- 
gence of  islands  and  continents  beneath  the  waters 
of  the  ocean — the  rapid  formation  of  conglomerates 
from  shells  and  corals  on  the  sea  shore — the  accu- 
mulation of  beach  and  gravel,  and  the  inhumation 
of  animals  and  vegetables — the  slow  deposition  of 
sediment  by  lakes  and  rivers — the  imbedding  of  in- 
numerable generations  of  insects,  and  the  formation 
of  limestone  from  their  almost  invisible  skeletons — 
the  construction  of  solid  stone  out  of  fragments  of 
bones,  and  rocks,  shivered  by  earthquakes  —  the 
engulfing,  in  estuaries  and  inland  seas,  of  land 
animals,  birds,  and  reptiles — the  consolidation  of 
both  organic  and  inorganic  substances  into  rock, 
by  the  infiltration  of  flint  and  lime  by  thermal 
waters  —  the  transmutation  of  submerged  forests 
into  coal  and  lignite — the  destructive  and  conser- 
vative effects  of  volcanic  eruptions — the  conversion 
of  sand,  gravel,  and  clay,  into  homogeneous  masses 
by  heat,  and  even  the  production  of  metalliferous 
veins  of  gold  and  silver — all  these  phenomena  have 
passed  in  review  before  us,  although  our  inquiries 
have  extended  through  periods  which,  however  vast 
and  remote  in  relation  to  the  records  of  our  race, 
are  but  brief  and  modern  in  the  physical  history  of 
the  earth. 


§  2.  SECONDARY  FORMATIONS.  289 

The  geological  events  previously  described,  al- 
though forming  a  connected  series,  may  be  divided 
into  periods,  each  of  which  is  marked  by  certain 
zoological  characters ;  namely,  1st.  The  modern,  or 
human  epoch;  2d.  the  elephantine,  characterised  by 
the  preponderance  of  large  pachydermata ;  3d.  the 
palcBotherian,  in  which  animals  allied  to  the  tapir 
prevailed,  and  Europe  presented  a  system  of  gulfs 
and  lakes. 

2.  SECONDARY  FORMATIONS. — I  hasten  to  the 
consideration  of  another  and  antecedent  geological 
epoch, — that  which  comprehends  the  Secondary 
Formations.  Hitherto  our  attention  has  been  prin- 
cipally directed  to  deposits  confined  within  com- 
paratively limited  areas,  as  the  basins  of  lakes, 
gulfs,  estuaries,  and  inland  seas ;  and  accumulations 
of  drifted  materials  produced  by  the  action  of 
torrents,  rivers,  and  inundations.  We  have  now 
arrived  on  the  shores  of  that  ocean,  of  whose 
spoils  the  existing  islands  and  continents  are  prin- 
cipally composed  ;  the  fathomless  depths  of  the 
ancient  seas  are  spread  before  us,  and  the  myriads 
of  beings  which  sported  in  their  waters,  and  lived 
and  died  in  those  profound  abysses,  remain,  like 
the  mummies  of  ancient  Egypt,  the  silent  yet  elo- 
quent teachers  of  their  own  eventful  history. 

A  reference  to  the  Tabular  Arrangement  of  the 

Strata  (Plate  VII.  and  page  194)  will  show  that 

the  secondary  formations  constitute  nine  principal 

subdivisions,    forming    four    natural    groups,    viz. 

u 


290  THE  WONDERS  OP  GEOLOGY.  LECT.  IV. 

the  cretaceous,  oolitic,  saliferous,  and  carboniferous 
systems,  each  containing  littoral,  marine,  and 
oceanic  deposits;  sandstones  having  been  formed 
amidst  the  agitated  waters  of  the  sea  shores,  clays 
in  tranquil  bays  and  gulfs,  and  limestones  in  deep 
water.  I  purpose,  in  the  present  discourse,  to  ex- 
plain the  geological  characters  of  the  first  two  of 
the  series,  namely,  the  CHALK  and  the  WEALDEN,* 
The  former  is  composed  of  rocks  that  have  been 
accumulated  in  the  depths  of  a  sea  of  great  extent ; 
the  latter,  of  the  sediments  of  a  vast  delta;  the 
one  affording  a  striking  illustration  of  the  nature  of 
oceanic,  and  the  other  of  fluviatile  deposits. 

In  the  diagram  (Plate  VII.)  the  wealden  (3*)  is 
represented  as  an  intercalation  between  the  chalk 
and  the  oolite  (3,  4),  because  it  is  of  limited  ex- 
tent, and  where  absent,  as  in  the  midland  counties  of 
England  and  on  the  continent,  the  chalk  lies  upon 
the  oolite,  as  will  be  shown  in  the  next  lecture.  As 
both  the  chalk  and  the  wealden  are  fully  developed 
in  the  south-east  of  England,  the  phenomena  about 
to  be  described  may  be  examined  with  but  little 
inconvenience;  and  an  extensive  collection  of  the 
peculiar  fossils  of  these  formations  may  be  seen  in 
my  museum. "j- 

*  The  term  Weald  is  derived  from  the  German  Wald,  a  wood 
or  forest.  The  Weald  of  Sussex  was  formerly  an  impenetrable 
forest,  called  Anderida  by  the  Romans,  and  Andredswald  by 
the  Saxons. 

f  Now  in  the  British  Museum.  See  Descriptive  Catalogue 
of  the  Mantellian  Museum,  8vo.  fifth  edition. 


§  3.  THE  CHALK  FORMATION.  291 

3.  THE  CHALK  FORMATION. — The  pure  white 
limestone,  called  chalk,  is  known  to  every  one ;  but 
in  the  nomenclature  of  geology,  the  name  is  applied 
to  a  group  of  deposits  very  dissimilar  in  their  litho- 
logical  composition,  but  agreeing  in  the  nature  of 
the  organic  remains  which  they  contain,  and  evi- 
dently referable  to  the  same  geological  epoch.  The 
series  essentially  consists  of  green  and  ferruginous 
sands,  clays,  marls,  and  grey  and  white  limestones, 
abounding  in  marine  remains.  With  this  expla- 
nation it  will  be  convenient  to  employ  the  term  in 
its  extended  sense.  The  chalk  formation  comprises 
the  following  subdivisions : — 

1.  Upper  chalk,  with  flints     ...      1  Craie  blanche  of  the 

2.  Lower  chalk,  without  flints     .     .      )  French  geologists. 

3.  Chalk  marl Craie  tufeau. 

4.  Firestone,  malm-rock,  upper  green  )  ^^  ^ 

sand,  or  glauconite     .     .     .     .      ) 

5.  Gait,  or  Folkstone  marl    .... 

6.  Shanklin,  or  lower  green  sand    .     .    Glauconie  sableuse. 

The  chalk  is  generally  white,  but  in  some  countries 
is  of  a  deep  red,  and  in  others  of  a  yellow  colour  ; 
nodules  and  veins  of  flint  occur  in  the  upper, 
but  seldom  in  the  lower  chalk.  The  marl  is  an 
argillaceous  limestone,  which  generally  prevails 
beneath  the  white  chalk  ;  it  sometimes  contains  a 
large  intermixture  of  green  sand,  and  then  is  called 
firestone,  or  glauconite.  The  gait  is  a  stiff,  blue  or 
black  clay,  abounding  in  shells,  which  frequently 
possess  a  pearly  lustre.  The  Shanklin,  or  lower 
green  sand,  is  a  triple  alternation  of  sands  and  sand- 
u2 


292  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

stone  with  clays  ;  beds  of  chert  and  fuller's  earth 
are  also  found  in  some  localities. 

On  the  continent,  the  series  of  deposits  here 
enumerated  is  largely  developed,  and  taken  as  a 
whole,  the  chalk  formation  may  be  described  as 
extending  over  a  great  part  of  the  British  Islands, 
Northern  France,  Germany,  Denmark,  Sweden, 
European  and  Asiatic  Russia,  and  of  the  United 
States  of  North  America.  Over  this  vast  extent, 
the  organic  remains  present  certain  general  cha- 
racters, sufficiently  obvious  to  determine  the  nature 
of  the  formation.  Whether  imbedded  in  pure  white 
limestone,  coarse  sandstone,  blue  clay,  loose  sand, 
or  compact  rock,  the  fossils  consist  of  the  same 
species  of  shells,  corals,  sponges,  echinites,  belem- 
nites,  ammonites,  and  other  marine  exuviae  ;  fishes, 
reptiles,  wood,  and  plants.  The  strata  are  boldly 
displayed  along  the  Hampshire,  Sussex,  and  Kentish 
coasts ;  the  precipitous  headland  of  Beachy  Head, 
and  the  cliffs  at  Dover  are  well  known ;  these 
natural  sections  exhibit  the  manner  in  which  the 
beds  have  been  disrupted,  and  thrown  into  various 
inclined  positions  (see  PL  9,  fig.  1).  At  Devizes,  in 
Wiltshire,  the  strata  lie  nearly  horizontal,  and  in  the 
following  order : — 1.  White  chalk.  2.  Glauconite. 
3.  Gait  4-.  Shanklin  Sands  (see  PL  9,  fig.  2). 

4-.    CHALK   AND    FLINT.* — The  white  chalk  is 

*  See  The 'Fossils  of  the  South  Downs,  or,  Illustrations 
the  Geology  of  Sussex,  1  vol.  4to.  with  42  plates.     Geology  of 
the  South-East  of  England,  1  vol.  8vo.     Dr.  Fitton's  Memoirs 


§  5.  FLINT  NODULES.  293 

composed  of  lime  and  carbonic  acid,  and  may  have 
been  precipitated  from  water  holding  lime  in  solu- 
tion, from  which  an  excess  of  carbonic  acid  was 
expelled.  But  a  large  proportion  of  the  purest 
chalk  appears  to  be  in  great  part,  if  not  wholly, 
composed  of  the  remains  of  corals  and  shells,  and 
in  some  quarries  whole  layers  are  formed  of  the 
ossicula  of  star-fish  and  other  radiaria,  with  micro- 
scopic species  of  polyparia  and  shells.*  The  nodules 
and  veins  of  flint  which  occur  in  the  chalk,  show  that 
water  holding  silex  in  solution  must  have  been  very 
abundant  during  the  cretaceous  period.  The  power 
possessed  by  thermal  waters  of  dissolving  silicious 
earth,  depositing  flint,  and  occasioning  the  silieifi- 
cation  of  vegetable  substances,  is  strikingly  exem- 
plified in  the  Geysers  of  Iceland,  as  I  have  already 
explained  (p.  83).  The  perfect  fluidity  of  the  silex 
before  consolidation,  is  shown  by  the  sharp  impres- 
sions which  the  flints  bear  of  shells  and  other  marine 
bodies ;  and  upon  breaking  the  nodules,  zoophytes, 
related  to  sponges  and  alcyonia,  with  other  organic 
remains,  are  found  enveloped ;  the  silicious  matter 
having  so  penetrated  the  delicate  structure  of  the 
originals,  that  polished  sections  display  the  most 
minute  organization  of  the  inclosed  bodies. 

5.  FLINT  NODULES. — Flints,  or  silicious  nodules, 

on  the  Shanklin,  or  Green  Sands,  in  which  many  of  the  fossils 
are  beautifully  delineated;  Geological  Transactions,  vol.  iv. 
New  Series. 

*  Mr.  Lonsdale. 


294  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

occur  in  the  chalk  in  horizontal  rows,  which  present 
some  degree  of  regularity,  but  are  placed  at  unequal 
distances  from  each  other.  This  arrangement  has 
probably  arisen  from  the  chalk  and  flint  having 
been  held  in  suspension  or  solution  in  the  same 
fluid,  and  precipitated  into  the  basin  of  the  ocean  : 
when  consolidation  took  place,  the  silicious  molecules 
separated  from  the  cretaceous,  on  the  well-known 
principles  of  chemical  affinity ;  the  sponges  and 
other  zoophytes  acting  as  nuclei  or  centres,  around 
which  the  silicious  matter  coagulated.  This  pro- 
cess receives  illustration  from  the  fact,  that  when 
different  substances  in  a  state  of  extreme  division 
are  mixed  together,  they  have  a  tendency  to  sepa- 
rate, and  re-arrange  themselves  in  masses  more 
nearly  homogeneous ;  thus  in  the  materials  pre- 
pared in  the  potteries,  a  separation  of  pounded  flint 
from  aluminous  earth  takes  place,  and  silicious  con- 
cretions are  formed,  if  the  mixture  be  not  constantly 
agitated.  The  marked  stratification  of  the  chalk 
shows  that  it  was  deposited  periodically ;  and  it  is 
not  unusual  to  find  veins  of  flint  running  through 
and  filling  up  crevices  in  the  strata  beneath ;  an 
appearance  that  can  only  be  attributed  to  the  lower 
beds  having  been  consolidated,  and  subsequently 
fissured,  before  the  superincumbent  stratum  was 
precipitated. 

6.  ORGANIC  REMAINS  IN  FLINT. — The  organic 
remains  which  usually  occur  in  the  chalk  are  also 
found  in  the  flints;  but  certain  fossils  prevail  far 


§  7.  SULPHURET  OF  IRON.  295 

more  abundantly  than  others  ;  a  circumstance  in 
all  probability  attributable  to  the  constituent  sub- 
stance of  the  original  having  been  favourable  to 
the  process  of  silicification.  The  softer  zoophytes, 
as  the  alcyonia,  spongiae,  &c.  absolutely  swarm  in 
the  flints ;  and  infusoria  are  equally  abundant. 
Fishes  are  occasionally  found  enveloped  in  a  flint 
nodule ;  and  their  minute  scales  have  been  detected 
by  Mr.  Reade  with  the  aid  of  the  microscope,  in 
almost  every  fragment  of  flint.  Wood  which  has 
been  perforated  by  lithodomi,  and  silicified,  is  not 
scarce ;  and  conferva?  and  fuci  are  sometimes  found 
floating,  as  it  were,  in  the  liquid  silex.  Bones  of 
reptiles  and  fishes  are  often,  impacted  in  a  mass  of 
flint,  but  in  no  instance  that  I  have  observed  has 
the  silex  permeated  the  osseous  structure.  When 
corals,  echini,  shells,  &c.  are  imbedded,  the  sub- 
stance of  the  fossils  is  calcareous,  not  silicious  ; 
they  appear  to  be  simply  enveloped  by  a  silicious 
paste,  which  had  not  the  power  of  penetrating  the 
interstices,  nor  of  producing  any  chemical  change. 

7.  SULPHURET  OF  IRON. — Iron  pyrites  is  the 
only  metalliferous  ore  that  occurs  abundantly  in  the 
chalk  of  England.  The  large  nodular  masses  that 
are  found  on  the  Downs  and  in  the  ploughed  fields, 
are  commonly  termed  thunderbolts.  This  mineral 
sometimes  forms  groups  of  octahedral  crystals 
of  great  elegance  and  regularity,  and  frequently 
occupies  the  cavities  of  shells  and  echini ;  terebra- 
tulee  and  pectens  also  occasionally  occur  in  masses 


296  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

of  this  substance.  The  bones  and  scales  of  the 
fishes  are  invariably  coloured  with  a  ferruginous 
stain,  arising  from  a  curious  chemical  process  ;  sul- 
phuretted hydrogen  was  evolved  during  the  putre- 
faction of  the  animal  substance,  but  the  sulphur 
entering  into  combination  with  the  iron  contained 
in  the  surrounding  water,  sulphuret  of  iron  was 
formed,  and  hence  the  fossil  fishes  derived  the  rich 
colour  which  so  beautifully  contrasts  with  the  white 
chalk  in  which  they  are  imbedded. 

8.  MAESTRICHT  BEDS. — I  have  described  the 
usual  lithological  characters  of  the  cretaceous  strata, 
arid  if  our  observations  were  restricted  to  these  de- 
posits as  they  occur  in  England,  the  difference 
between  the  uppermost  secondary  formation  and 
the  superimposed  tertiary  would  be  most  striking, 
both  as  regards  the  nature  of  the  rocks  and  their 
organic  remains.  But,  as  I  shall  hereafter  explain, 
the  white  chalk  of  England  appears  to  have  been 
formed  in  the  profound  depths  of  the  sea,  for  we 
have  rarely  any  intermixture  of  terrestrial  or  littoral 
productions  ;  even  pebbles  are  of  unfrequent  occur- 
rence. At  Castle  Hill,  near  Newhaven  (p.  223), 
and  at  Alum  Bay,  in  the  Isle  of  Wight  (p.  224), 
the  cerithia  (Tab.  38,  fig.  4),  turritella,  and  other 
tertiary  shells,  abound  in  the  sand  and  clay  spread 
over  the  surface  of  the  chalk,  in  which  no  similar 
shells  can  be  detected.  On  the  continent,  how- 
ever, there  exist  deposits  which  form,  as  it  were,  a 
link  between  the  tertiary  and  the  secondary.  In 


§  9.         ST.  PETER'S  MOUNTAIN,  NEAR  MAESTRICHT.        297 

the  valley  of  the  Meuse  there  is  a  fine  series  of 
strata,  the  uppermost  of  which  contains  many 
genera  of  shells  that  are  plentiful  in  the  tertiary, 
and  passing  imperceptibly  into  limestone  with  cre- 
taceous fossils  and  flint  nodules,  is  finally  lost  in 
the  chalk.  At  Gosau,  in  the  Eastern  Alps,  beds 
occur  which  appear  to  belong  to  the  same  interme- 
diate era ;  and  in  the  United  States,  the  researches 
of  Dr.  Morton  have  proved  the  existence  of  analo- 
gous deposits. 

9.  ST.  PETER'S  MOUNTAIN,  NEAR  MAESTRICHT. 
— The  quarries  of  St.  Peter's  Mountain  have  long 
been  celebrated  for  their  remarkable  fossils ;  but 
the  true  geological  characters  of  the  strata  were 
first  determined  by  Dr.  Fitton.  St.  Peter's  Moun- 
tain, in  which  the  quarries  are  situated,  is  a  cape 
or  headland  between  the  Meuse  and  the  Jaar,  and 
forms  the  extremity  of  a  range  of  hills  which  bounds 
the  western  side  of  the  valley  of  the  Meuse.  The 
mountain  commences  at  the  distance  of  a  mile 
south  of  Maestricht,  and  extends  in  a  direction 
towards  Liege  for  about  three  leagues  ;  it  presents 
an  almost  perpendicular  escarpment*  towards  the 
river.  A  section  of  the  hills  affords  the  following 
succession  of  strata  : — 

1.  Lowermost :  white  chalk,  with  layers  of  flint 
nodules. 

2.  Chalk  very  hard  and  gritty. 

3.  Calcareous  freestone  of  a  yellow  fawn  colour, 
abounding  in   fossils.      Numerous   layers  of  flint 


298  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

occur  throughout  the  entire  series,  and  present  the 
usual  characters  of  the  silicious  nodules  of  the 
chalk  formation.  The  Maestricht  freestone  is  so 
extremely  soft  in  the  quarry,  that  it  may  easily  be 
cut  with  a  knife,  but  it  becomes  harder  and  of  a 
lighter  colour  by  exposure  to  the  air.*  The  beds 
of  limestone  have  a  total  thickness  of  about  500 
feet.  Excavations  have  for  centuries  been  carried 
on  in  the  strata  of  freestone,  and  from  the  immense 
quantities  of  stone  removed,  extensive  caverns  and 
galleries  now  traverse  the  heart  of  the  mountain. -j- 
Shells,  corals,  Crustacea,  teeth  of  fishes,  and  other 
marine  remains,  occur  in  profusion ;  with  wood 
perforated  by  lithodomi,  and  the  bones  of  a  large 
and  very  remarkable  reptile. 

10.  THE  MOS^ESAURUS  ;  OR  FOSSIL  REPTILE  OF 
MAESTRICHT. —  The  bones  and  teeth  of  an  un- 
known animal  which  were  occasionally  found  in 
the  limestone,  had  long  since  directed  the  attention 
of  naturalists  to  the  quarries  of  St.  Peter's  Moun- 
tain. In  1770  M.  Hoffmann,  who  was  forming  a 
collection  of  organic  remains,  had  the  good  fortune 

*  The  avidity  of  collectors  has  induced  the  quarrymen  to 
practise  an  ingenious  fraud  upon  strangers :  teeth  and  bones  of 
the  horse,  boar,  &c.  are  carefully  imbedded  in  blocks  of  the 
limestone  while  it  is  soft ;  and  when  the  stone  becomes  hard, 
the  specimens  are  offered  for  sale  as  genuine  fossils  from  the 
quarries.  The  deception  may  be  detected  by  immersing  the 
specimens  in  water. 

f  See  Hist.  Nat.  de  la  Montagne  de  St.  Pierre,  by  Faujas 
St  Fond,  1  vol.  4to.  with  splendid  engravings. 


§  10.  THE  MOS^SAURUS.  299 

to  discover  a  specimen,  which  has  conferred  addi- 
tional interest  on  this  locality  :  some  workmen,  on 
blasting  the  rock  in  one  of  the  caverns  of  the 


TAB.  47.— REMAINS  OF  THE  MOSJESAURUS. 

Discovered  at  Maestricht,  by  M.  Hoffmann,  in  1770;   now  in  the 
Museum  at  Paris. 

(Four  and  a  half  feet  by  two  and  a  half.) 

interior  of  the  mountain,  perceived,  to  their  asto- 
nishment, the  jaws  of  an  enormous  animal  attached 
to  the  roof  of  the  chasm.  The  discovery  was 
immediately  made  known  to  M.  Hoffmann,  who 
repaired  to  the  spot,  and  for  weeks  presided  over 
the  arduous  task  of  separating  from  the  rock  the 
mass  of  stone  containing  the  remains.  His  labours 
were  at  length  repaid  by  the  successful  extrication 


300  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

of  the  specimen,  which  he  conveyed  in  triumph  to 
his  house.     Unfortunately,  the  canon  of  the  cathe- 
dral, which  stands  on  the  mountain,  claimed  the 
fossil  in  right  of  being  lord  of  the  manor,  and  suc- 
ceeded, by  a  most  unjust  and  expensive  law-suit,  in 
obtaining  this  precious  relic  (Tab.  47).    It  remained 
in  his  possession  for  years,  and  Hoffmann  died  with- 
out regaining  his  treasure,  or  receiving  any  com- 
pensation.    The  French  Revolution  broke  out,  and 
the  armies  of  the  Republic  advanced  to  the  gates 
of  Maestricht ;  the  town  was  bombarded,  but  by 
desire  of  the  committee  of  savans,  who  accompanied 
the  French  troops,  the  artillery  was  not  allowed 
to  play  on  that  part  of  the  city  in  which  the  cele- 
brated fossil  was  known  to  be  contained.     In  the 
meanwhile   the    canon,    shrewdly   suspecting   why 
such  peculiar  favour  was  shown  to  his  residence, 
concealed  the  specimen  in  a  secret  vault ;  but  when 
the  city  was  taken,  the  French  authorities  compelled 
him  to  give  up  his  ill-gotten  prize,  which  was  im- 
mediately transmitted  to  the  Jardin  des  Plantes,  at 
Paris,  where  it  still  forms  one  of  the  most  striking 
objects  in  that  magnificent  collection.     It  is  but 
just  to  add,  that  the  relatives  of  Hoffmann  were 
rewarded  by  the  French  commissioners.    The  model 
of  this  specimen  in  my  museum  was  presented  to 
me  by  Baron  Cuvier  ;  it  consists  of  the  jaws,  teeth, 
palate-bone,  vertebrae,  and  os  guadratum,  a  bone 
possessed  by  some  reptiles,  and  in  which  the  audi- 
tory cells  are  contained.    There  are  portions  of  jaws 


§  11.        LOWER  GROUP  OF  THE  CHALK  FORMATION.        301 

with  teeth  of  the  mosaesaurus  in  the  British  Museum. 
The  original  was  a  reptile,  holding  an  intermediate 
place  between  the  monitor  and  iguana,  about  twenty- 
five  feet  long,  and  furnished  with  a  tail  of  such 
construction  as  must  have  rendered  it  a  powerful 
oar,  enabling  the  animal  to  stem  the  waves  of  the 
ocean,  of  which  Cuvier  supposes  it  to  have  been  an 
inhabitant.  The  vertebrae  before  you  belong  to  the 
mosaesaurus,  and  were  discovered  in  a  chalk  quarry 
near  Lewes.*  A  remarkable  specimen  was  found 
a  short  time  since  in  the  chalk  of  Kemp-town  ;  it 
is  a  vertebra  of  the  tail,  partially  invested  with 
flint,  which  has  consolidated  around  it  without  ob- 
scuring its  essential  characters.  These  teeth,  from 
North  America,  collected  by  Dr.  Morton,  appear 
to  belong  to  the  same  species  as  those  from  Maes- 
tricht,  and  additional  proof  is  thus  afforded  of  the 
original  extension  of  the  ocean  of  the  chalk  over 
the  area  now  occupied  by  the  Atlantic. 

11.  LOWER  GROUP  OF  THE  CHALK  FORMATION. 
— The  lower  division  of  the  chalk  formation  com- 
prises the  marl,  glauconite,  gait,  and  Shanklin  sands 
(see  page  291);  and  these  deposits  are  constant  in 
their  character  and  position  in  the  south-east  of 
England.  Near  Southbourn,  on  the  Sussex  coast, 
the  marl,  gait,  and  Shanklin  sand,  may  be  seen  rising 
in  succession  on  the  north  of  the  South  Downs;  while 
on  the  coast  of  Kent,  the  same  group  emerges  from 
beneath  the  chalk  on  the  south  side  of  the  North 
*  Geology  of  the  South-East  of  England,  p.  146. 


302 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


Downs  (see  Plate  IX.  fig.  1).  The  relative  position 
of  these  beds  is  well  displayed  at  Copt  Point,  near 
Folkstone  ;  the  gait  constitutes  the  immediate  face 
of  the  cliff,  and  reposes  on  the.  Shanklin  sand,  which 
forms  the  base  (Tab.  48).  Eastware  Bay  is  cele- 
brated for  the  abundance  of  gait  fossils,  which  are 
constantly  being  washed  out  of  the  marl  by  the 

Folkstone  Hill. 


TAB.  48. — SECTION  AT  EASTWARE  BAY,  NEAR  FOLKSTONE. 

1.  The  chalk.    2.  Marl  and  glauconite.    3.  Gait.    4.  Shanklin  sand. 

(By  Dr.  Fitton.) 

action  of  the  sea.  The  series  may  be  traced  with 
more  or  less  distinctness  around  the  denudation  of 
the  wealden,  encircling  the  fresh-water  strata.  The 
lowermost  member,  the  Shanklin  sand,  rises  into 
more  importance  towards  the  west,  and  in  Surrey, 
Hampshire,  and  western  Sussex,  forms  a  line  of 
bold  hills,  which  run  parallel  with  the  chalk  downs, 
and  rival  them  in  altitude;  a  valley  of  gait  generally 
intervenes  between  the  sand  and  chalk,  as  at  Rei- 
gate  (Plate  IX.  i.)  The  Shanklin  sand  is  subdivided 


§  12.  ORGANIC  REMAINS  OF  THE  CHALK.  303 

into  three  groups.  The  uppermost,  which  is  almost 
100  feet  in  thickness,  consists  of  red,  green,  white, 
grey,  and  yellow  sand,  with  concretions  of  chert 
and  chalcedony,  which,  in  the  Blackdown  hills  of 
Devonshire,  contain  immense  numbers  of  silicified 
shells.  The  beds  of  the  second  group  have  a  large 
admixture  of  clay  and  oxide  of  iron,  and  are  so 
retentive,  that  pools  of  water  are  numerous  in  the 
tracts  they  occupy,  and  springs  burst  forth  at  their 
junction  with  the  superincumbent  sand.  The  lower- 
most division  abounds  in  green  and  grey  sands,  and 
contains  numerous  concretionary  masses  and  beds 
of  the  grey  arenaceous  limestone,  well  known  as 
the  "  Kentish  rag."  At  Shanklin  Chine,  in  the  Isle 
of  Wight,  these  beds  form  the  most  characteristic 
feature  of  that  picturesque  spot,  from  whence  the 
name  of  the  strata  is  derived.  In  the  north-east  of 
Ireland,  the  Shanklin  sand  constitutes  an  important 
feature.  On  the  continent  it  is  found  accompanying 
the  upper  members  of  the  chalk  formation,  and  is 
well  displayed  in  Saxony,  and  along  the  Alps  and 
the  Carpathian  mountains.  In  North  America, 
arenaceous  strata  appear  to  be  the  equivalent  of  the 
chalk  of  Europe,  for  they  abound  in  the  usual 
cretaceous  fossils,  as  ammonites,  nautili,  hamites, 
scaphites,  belemnites,  echinites,  &c. 

12.  ORGANIC  REMAINS  OF  THE  CHALK. — The 
fossils  of  the  chalk  are  very  numerous,  and  com- 
prise all  the  usual  forms  of  marine  animals,  with  the 
exception  of  cetacea.  Particular  genera  and  species 


,304  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

appear,  however,  to  be  restricted  to  certain  sub- 
divisions of  the  formation.  Thus  in  the  white  chalk, 
there  are  many  species  of  shells  that  do  not  occur 
in  the  other  divisions  of  the  group.  The  marl  and 
gait  are  also  characterised  by  peculiar  forms,  and 
the  Shanklin  sands  abound  in  shells  and  zoophytes, 
that  are  wanting  in  the  other  cretaceous  beds.  The 
genera  and  species  of  the  mollusca  must  therefore 
have  varied  during  the  period  of  the  deposition  of 
the  chalk ;  some  kinds  prevailed  at  the  commence- 
ment of  the  formation,  and  became  extinct  at  a 
subsequent  epoch  ;  while  other  forms  appear  for 
the  first  time.  Some  localities  are  also  found  to 
abound  in  species  which  do  not  occur  in  others ; 
these  shells  must  therefore  have  been  spread  over 
limited  areas  ;  in  other  words,  the  inhabitants  of 
the  chalk  ocean  had  geographical  limits  assigned 
them,  as  is  the  case  with  the  existing  species. 

The  mode  of  preservation  varies  in  the  different 
beds.  The  shells,  stony  polyparia,  and  radiaria  of 
the  white  chalk,  are  generally  transmuted  into  car- 
bonate of  lime  having  a  spathose  structure,  doubtless 
the  result  of  high  temperature,  acting  under  great 
pressure  (see  page  91).  Their  cavities  are  frequently 
filled  with  chalk,  flint,  or  sulphuret  of  iron ;  in 
many  instances  they  are  hollow,'  or  lined  with  crys- 
tals of  carbonate  of  lime.  The  softer  zoophytes 
are  silicified,  and  there  is  scarcely  a  flint  nodule  in 
which  their  remains  may  not  be  traced.  The  bones 
of  reptiles  and  fishes,  and  the  coverings  of  Crustacea, 


§  12.  ORGANIC  REMAINS  OF  THE  CHALK.  305 

are  in  a  friable  state,  and  stained  with  sulphuret  of 
iron.  The  teeth  and  scales  of  the  fishes  present  a 
high  polish,  and  are  coloured  by  a  ferruginous  im- 
pregnation. Wood  occurs  in  the  state  of  lignite, 
and  in  brown  friable  masses,  which  quickly  decom- 
pose upon  exposure  to  the  air,  but  when  enveloped 
in  flint,  the  structure  is  well  preserved ;  like  the 
fossil  wood  of  the  tertiary,  it  has  evidently  been 
drifted,  and  is  perforated  by  teredines  ;  the  fissures 
are  often  filled  with  glittering  pyrites. 

In  the  Gait,  the  nacreous  covering  of  the  shells  is 
commonly  preserved,  and  the  ammonites  and  nautili 
of  Folkstone  rival  in  beauty  the  shells  of  the  London 
clay,  and,  like  them  .are  subject  to  decomposition. 
The  Green-sand  fossils  are  generally  silicified,  and 
the  whetstone  pits  of  Devonshire  are  celebrated  for 
the  variety  and  chalcedonic  state  of  the  shells  in 
which  the  sandstone  abounds. 

The  organic  remains  of  the  chalk  formation  al- 
ready known,  amount  to  many  hundred  species  of 
shells,  corals,  radiaria,  &c.  The  most  distinctive 
zoological  character,  is  the  abundance  of  belemnites, 
echinites,  and  ammonites :  the  latter  are  the  shells 
of  an  extinct  race  of  cephalopoda,  which  appear 
for  the  first  time  in  the  chalk,  no  traces  of  their 
remains  having  been  discovered  in  the  tertiary 
formations.  My  collection,  consisting  of  many 
thousand  fossils  from  the  chalk  formations  of  Eng- 
land and  America,  displays  the  usual  genera  and 
species,  together  with  many  that  are  exceedingly 


306  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

rare.     I  will  illustrate  this  subject  by  a  selection  of 
a  few  specimens  from  each  class. 

13.  FOSSIL  VEGETABLES. — The  flora  of  the  chalk, 
as  I  have  already  remarked,  offers  but  little  variety. 
Fuci,  or  sea-weeds,  occur  in  some  localities  in  great 
abundance.  There  is  one  species  of  Fucus  (Fucoides 
Targionii,  Tab.  49,)  that  abounds  in  the  malm  rock 


TAB.  49.— FOSSIL  FUCUS  IN  MALM  ROCK,  FROM  BIGXOR  PARK. 

(Fueoides  Targionii.) 

of  Western  Sussex,  particularly  at  Bignor,  the  seat 
of  my  friend  John  Hawkins,  Esq.  F.R.  S.,  where 
almost  every  fragment  of  the  rock  is  marked  with  its 
meandering  forms.  Confervce  occasionally  are  seen 
in  the  flints.  Plants  allied  to  Zostera  occur  in  the 
chalk  of  the  Isle  d'Aix,  and  drifted  wood  abounds 
in  the  line  of  junction  between  the  gait  and  green 
sand.  In  the  quarry  of  Kentish  rag,  of  Mr.W.  H. 
Bensted,  of  Maidstone,  there  have  been  discovered 


§14. 


ZOOPHYTES  OF  THE  CHALK. 


307 


fir-cones,  large  masses  of  perforated  wood,  and  the 
stem  of  a  plant  allied  to  the  yucca.  I  reserve  a 
more  particular  description  of  these  remains  for  the 
lecture  on  fossil  botany. 

14-.  FOSSIL  ZOOPHYTES. — I  have  already  men- 
tioned how  numerous  are  the  softer  zoophytes  in 


TAB.  50. — CORALS  OF  THE  CHALK. 

Fig.  1 .  External  surface  of  Turbinolia  Konigi  from  the  gait :  the  fossil  is 
attached  to  the  marl  by  the  disk,  the  base  lying  uppermost  and  ex- 
posed. 2.  The  disk,  or  iipper  surface  of  Turbinolia  Konigi,  imbedded  in 
gait.  3.  Caryophyllia  centralis  from  the  chalk  near  Lewes.  4.  Fungia 
in  limestone,  from  Maestricht.  5.  Gorgonia,  from  Maestricht. 

the  flints.  In  the  white  chalk  stony  corals  are 
found  but  rarely,  while  the  Maestricht  beds  contain 
them  in  great  abundance.  A  small  caryopliyllia 


308  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

(Tab.  50,  fig.  3)  is  not  unusual  in  the  English  white 
chalk,  and  a  species  of  turbinolia  (Tab.  50,  fig.  1,  2) 
occurs  in  the  gait.  I  have  several  unique  speci- 
mens of  other  genera  ;  but  the  absence  of  the  large 
madrepores  and  stony  corals  is  a  remarkable  fact, 
and  accords  with  the  evidence  derived  from  other 
sources,  to  prove  that  we  are  examining  the  pro- 
found abyss  of  an  ocean ;  for  the  economy  of  the 
living  corals  fits  them  to  live  only  in  waters  of  mode- 
rate depth.  It  would  be  tedious  to  repeat  to  you 
the  names  which  naturalists  have  assigned  to  the 
zoophytes  of  the  chalk  ;  let  it  suffice  to  observe, 
that  the  more  delicate  forms,  as  flustra,  millepora, 
cellepora,  spongia,  alcyonium,  &c.  are  very  abun- 
dant, particularly  in  some  localities  of  the  Shanklin 
sand ;  for  instance,  the  quarries  at  Faringdon,  in 
Berkshire,  which  literally  swarm  with  polyparia. 
The  nature  of  these  fossils  will  be  explained  in  a 
future  lecture.  There  is  a  zoophyte,  well  known 
to  collectors  of  Sussex  pebbles  by  the  name  of 
petrified  sea-anemone,  from  its  supposed  resemblance 
to  the  living  actinia  (PL  6,  fig.  8)  ;  but  the  original 
of  this  fossil  was  a  very  different  creature.  From 
an  extensive  suite  of  specimens,  I  have  ascertained 
that  it  was  of  a  subglobular  form,  with  a  central 
opening,  from  which  numerous  tubes  radiated ;  and 
these  are  oftentimes  exquisitely  preserved  in  flint. 
The  external  surface  frequently  exhibits  the  remains 
of  crucial  spines,  similar  to  those  possessed  by  the 
recent  alcyonia. 


§  15.  RADIARIA,  CRINOIDEA,  &c.  309 

15.  RADIARIA,  CRINOIDEA,  &c. — The  crinoidea, 
or  lily-shaped  animals,  are  but  sparingly  distributed 
in  the  chalk — a  circumstance,  as  you  will  hereafter 


TAB.  51.— MARSUPITE  FROM  THE  CHALK. 

(Restored  from  specimens  pretented  me  by  the  Rev.  H.  Hoper,  and 
G.  A.  Coombe,  Esq.  of  Arundel.) 

find,  strikingly  contrasting  with  the  zoological  cha- 
racters of  the  older  secondary  formations.  Stems 
of  encrinites  occur  in  the  chalk  and  gait ;  and  there 
is  a  small  species  of  apiocrinite,  which  is  peculiar  to 
this  formation.*  The  most  remarkable  fossil  of  this 
class  is  the  marsupite,  which  I  have  thus  named 
from  its  resemblance,  when  closed,  to  a  purse.  The 
marsupite  (Tab.  51)  was  a  molluscous  animal,  of  a 
*  Geology  of  the  South- East  of  England,  p.  111. 


310  THE  WONDERS  OF  GEOLOGY.  LECT.  IV- 

sub-ovate  form,  having  the  mouth,  which  was  sur- 
rounded by  arms,  or  tentacula,  in  the  centre.  The 
skeleton  was  composed  of  crustaceous,  hexagonal 
plates,  and  the  arms,  which  are  subdivided  into 
numerous  branches,  were  formed  of  ossicula,  or 
little  bones ;  the  whole  was  invested  with  a  mus- 
cular tissue,  or  membrane.  When  floating,  the 
creature  could  spread  out  the  tentacula  like  a  net, 
and  by  closing  them,  seize  its  prey  and  convey  it 
to  the  mouth.  This  figure  (Tab.  51)  is  restored 
from  specimens  which  separately  exhibit  the  parts 
here  represented. 

Asterice,  or  star-fishy  are  occasionally  found  in 
great  perfection  in  the  chalk ;  my  friend,  the  Rev. 
Thomas  Cooke,  has  discovered  several  remarkably 
fine  impressions  in  flint,  on  the  South  Downs,  near 
Brighton.  The  whetstone  of  Devonshire  affords 
similar  remains. 

16.  ECHINITES. — Those  remarkable  animals,  the 
echini,  or  sea-urchins,  are  too  well  known  to  re- 
quire minute  description.  Their  spherical  shell, 
or  skeleton,  is  made  up  of  polygonal  plates,  closely 
fitted  to  each  other ;  and  the  surface  is  divided 
vertically,  by  bands  like  the  meridians  of  a  globe, 
having  rows  of  double  perforations.  The  shell  is 
studded  over  with  papillae,  which  vary  in  size,  in 
the  different  species,  from  mere  granular  points  to 
large  well-defined  tubercles.  To  these  papillae, 
spines  are  attached,  which  also  present  great  variety 
of  figure  and  decoration.  These  are  the  instruments 


ECHINITES. 


311 


of  motion,  and,  as  on  the  death  of  the  animal,  the 
tendons  by  which  the  spines  were  fixed  to  the  shell 
decompose,  the  extreme  rarity  of  fossil  specimens, 
with  these  processes  in  their  natural  position,  is 
readily  explained.  The  echini,  both  recent  and 


TAB.  52. — ECHINITES  AKD  SPINES  FROM  THE  CHALK. 

Fig.  1.  Cidaris  diadema.  2,  4,  9.  Spines  of  cidares.  3.  Nucleolites. 
5.  Ananchytes  cretosus.  6.  Tubercle  of  a  cidaris.  7.  Spatangus  cor- 
marinum.  8.  Spines  and  portion  of  the  shell  of  a  cidaris  in  flint. 

fossil,  differ  greatly  in  form  and  structure  ;  they 
are  arranged  into  numerous  sub-genera,  for  the 
convenience  of  study,  but  I  can  notice  only  a  few 
of  the  usual  varieties. 

The   helmet-shaped   echinites   (fig.  5)   are   ex- 
tremely abundant,  and  in  some  localities  occur  in 


312  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

shoals,  and  in  every  gradation  from  the  young  to 
the  adult  state.  Silicious  casts  of  echini,  formed 
by  the  decomposition  and  removal  of  the  shell  from 
the  flint  with  which  they  were  filled,  are  common 
in  gravel  and  on  ploughed  lands.  The  cordiform 
variety  (fig.  7)  is  very  abundant,  and  gives  rise  to 
the  heart-shaped  flints  of  our  gravel-pits.  The 
elliptical  species  (fig.  3)  is  common  in  the  green 
sand.  The  hemispherical  echini  are  beautifully 
embossed  with  papillae :  a  small  species  (fig.  1)  is 
not  uncommon  in  the  chalk  and  flints  of  Kent; 
the  larger  varieties  possess  tubercles,  surrounded  by 
elegant  margins  (fig.  6),  and  are  otherwise  richly 
ornamented.  Some  spines  are  slender,  and  covered 
with  asperities  (fig.  2);  others  almost  smooth  (fig.  9), 
and  club-shaped  (fig.  4);  it  is  seldom  that  the 
spines  are  found  imbedded  in  contact  with  the 
shell  (fig.  8). 

17.  SHELLS  OF  THE  CHALK. — The  bivalve  shells, 
or  conchifera  of  the  chalk,  are  very  numerous ;  of 
one  genus  alone  (terebratula)  above  fifty  species 
are  enumerated.  Oysters,  scallops,  areas,  tellens, 
and  other  familiar  marine  shells  abound,  but  the 
species  differ  from  the  recent.  With  these  known 
genera  are  many  which,  so  far  as  our  present  know- 
ledge of  the  inhabitants  of  the  deep  extends,  are 
extinct.  Two  or  three  species  of  cirrus,  or  trochus, 
are  not  unusual  in  the  white  chalk ;  but  the  simple 
univalves  are  few ;  and  the  only  specimen  of  a  large 
simple  spiral  univalve  with  which  I  am  acquainted 


§17. 


SHELLS  OF  THE  CHALK. 


313 


is  a  species  of  dolium,  figured  by  Sowerby.*  The 
Maastricht  beds,  as  I  have  before  remarked,  offer 
many  exceptions  to  the  usual  fossils  of  the  chalk. 
A  large  volute  (  V.  Faujasii)  is  found  in  the  flint 


TAB.  53. — SHELLS  OF  THE  CHALK. 

Fig.  1.  Inoceramus  concentricus.  2.  Turrilites  costatus.  3.  Inoceramus 
sulcatus.  4.  Inoceramus  Lamarckii.  5.  Belemnites  Listen.  6.  Ha- 
mites.  7.  Ammonites  Mantellii.  8.  Plagiostoma  spinosum.  9.  Am- 
monites Sussexiensiu. 

nodules  of  St.  Peter's  Mountain,  with  baculites,  am- 
monites, and  other  characteristic  chalk  fossils.     In 
the  marl  at  Ramsey,  near  Lewes,  I  have  discovered  a 
*  Mineral  Conchology,  vol.  v.  Tab.  426. 


314  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

few  genera  of  simple  univalves  not  previously  known 
in  the  chalk.  The  sub-globular  terebratulae,  both 
the  common  and  the  striated  varieties,  are  very 
abundant.  Another  bivalve  equally  numerous  is  an 
elegant  shell,  having  one  valve  covered  with  long 
spines  (Tab.  53,  fig.  8),  the  Plagiostoma  spinosum,* 
a  characteristic  species  of  this  formation.  A  bivalve 
having  a  fibrous  structure,  (Inoceramus,  Tab.  53, 
fig.  4,)  very  brittle,  with  a  crenulated  hinge  of  a 
peculiar  construction,  presents  numerous  species  ; 
some  of  which  are  small  and  delicately  striated,  and 
others  two  feet  in  diameter,  and  deeply  furrowed. 
The  substance  of  these  shells  closely  resembles  in 
structure  that  of  the  recent  pinnce ;  from  their 
fragility,  fragments  are  very  common  in  chalk,  flint, 
and  even  in  pyrites.  The  Gait  contains  two  species 
of  this  genus,  which  appear  to  be  restricted  to  this 
division  of  the  chalk,  and  have  been  found  in  almost 
every  locality ;  they  are  the  Inoceramus  concentricus 
(Tab.  53,  fig.  1,)  and  I.  sulcatus  (Tab.  53,  fig.  3) ; 
a  hybrid  occurs  in  the  Folkstone  beds,  partaking  of 
the  characters  of  both.  I  have  discovered  a  species 
of  spherulite  (S.  Morfoni)  in  the  chalk  near  Lewes, 
in  Sussex ;  but  hippurites,  so  common  in  the  cre- 
taceous strata  of  the  continent,  have  not  been 
noticed. 

*  Plagiostoma. — Viscount  D'Archiac  informs  me  that  the 
shells  of  this  genus  are  true  spondyli,  and  that  the  triangular 
vacancy  in  the  lower  valve  is  occasioned  by  the  loss  of  that  por- 
tion of  the  hinge  which  characterises  the  recent  spondylus. 


§  18.          CEPHALOPODA,  AND  CHAMBERED  SHELLS.          315 

The  shells  of  the  green  sand  amount  to  many 
hundred  species  :  those  of  the  whetstone  pits  of 
Blackdown,  in  Devonshire,  are  changed  either  into 
silex,  jasper,  or  chalcedony.* 

18.  CEPHALOPODA,  AND  CHAMBERED  SHELLS. — 
The  most  peculiar  and  striking  feature  of  the  organic 
remains  of  the  chalk,  as  contrasted  with  those  of  the 
tertiary  and  modern  deposits,  is  the  vast  preponder- 
ance of  multilocular  cephalopoda.  In  the  tertiary, 
and  in  the  existing  tropical  seas,  one  genus  (the 
nautilus)  occurs  abundantly.  The  beauty,  elegant 
form,  and  remarkable  internal  structure  of  the 
recent  shell,  have  rendered  it  in  all  ages  an  object 
of  admiration  ;  yet  an  accurate  knowledge  of  the 
nature  and  structure  of  the  animal  to  which  it 
belonged  has  but  recently  been  obtained.  Dr. 
Buckland  has  given  a  lucid  account  both  of  the 
recent  and  fossil  cephalopoda ; -f-  my  remarks. on 
this  subject  will  therefore  be  very  concise. 

The  sepia,  or  cuttle-fish  of  our  seas,  is  of  an 
oblong  form,  composed  of  a  jelly-like  substance, 
covered  with  a  tough  skin ;  the  mouth,  which  is 
central,  is  furnished  with  horny  mandibles,  much 
resembling  the  beak  of  a  parrot.  The  animal  has 
two  large  eyes,  and  eight  arms,  studded  with  rows 
of  little  cups,  or  suckers,  which  are  powerful  instru- 
ments both  of  locomotion  and  prehension.  The 

*  Dr.  Fitton's  Memoir  on  the  Shanklin  sands  contains  repre- 
sentations of  the  usual  shells  and  zoophytes  of  those  strata, 
t  Bridgewater  Essay,  p.  333,  et  seg. 


316  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

soft  body  of  the  sepia  is  supported  by  a  skeleton 
formed  of  a  single  bone  of  very  extraordinary  struc- 
ture ;  when  dried  and  reduced  to  powder  it  is  the 
substance  called  pounce.  The  cuttle-fish  has  the 
power  of  secreting  a  dark-coloured  fluid,  or  ink, 
which  it  ejects  when  pursued,  and  by  thus  rendering 
the  water  turbid,  escapes  from  its  enemies.  This 
fluid  is  contained  in  a  bag,  and  forms,  when  pro- 
perly prepared,  the  sepia  colour  employed  in  the 
arts,  and  enters  into  the  composition  of  Indian  ink. 
This  brief  sketch  of  the  natural  history  of  the 
cuttle-fish,  will  enable  us  to  understand  the  habits 
and  economy  of  the  beings  whose  fossil  remains  I 
am  about  to  describe. 

19.  THE  BELEMNITE. — One  of  the  most  common 
fossils  of  the  chalk  is  an  elongated  conical  stone,  of 
a  crystalline,  radiated  structure,  and  generally  of  a 
brown  colour,  called  belemnite.  The  pits  in  Sussex, 
Kent,  Norfolk,  and  indeed  every  locality  of  the 
chalk,  contain  these  bodies ;  and  some  limestones  on 
the  continent  are  almost  wholly  composed  of  them. 
The  belemnite  presents  considerable  variety  of  form, 
but  in  every  species  the  structure  consists  of  a 
spathose  radiated  substance,  terminating  in  a  point, 
(Tab.  54,  fig.  2,)  and  having  at  the  opposite  and 
largest  end  a  conical  cavity,  in  which  was  situated 
a  shell  of  like  form,  divided  into  septa  or  chambers, 
as  seen  in  the  drawing  (Tab.  54,  fig.  1) :  this  shell 
is  commonly  wanting  in  the  specimens  found  in  the 
chalk.  Dr.  Buckland  has  admirably  explained  the 


§20. 


THE  NAUTILUS. 


317 


nature  of  the  belemnite,  and  given  the  solution  of  a 
problem  which  had  long  been  attempted  in  vain. 
The  belemnite  is  the  bone  of  a  creature  allied  to 
the  cuttle-fish,  and  in  this  representation  (Tab.  54, 
fig.  1,)  its  situation  in  the  body  of  the  animal,  and 
connexion  with  the  ink-bag,  are  so  clearly  shown, 


TAB.  54. — BELEMNITE  AND  NAUTILUS. 

Fig.  1.  Section  of  a  restored  Belemno-sepia,  from  Dr.  Buckland ;  a,  the 
ink-bag;  b,  the  belemnite.  2.  Belemnites  Listeri.  3.  Section  of  the 
shell,  with  the  animal,  of  the  recent  nautilus,  from  Professor  Owen's 
Memoir ;  a,  the  animal  in  the  outer  chamber. 

as  to  require  no  further  comment.  The  belemnite 
sometimes  occurs  with  the  laminated,  external, 
horny  sheath,  the  conical,  chambered  shell,  the 
ink-bag,  and  the  fibro-calcareous  bone,  in  their 
natural  position ;  the  inspissated  contents  of  the 
bag,  the  fossil  sepia,  has  actually  been  employed  as 
a  pigment  by  one  of  our  most  eminent  artists. 

20.  THE  NAUTILUS. — The  shell  of  the  nautilus 
consists  internally  of  a  series  of  chambers,  which 


318  THE  WONDERS  OF  GEOLOGY.  LECT.  IV 

are  pierced  through  the  middle  by  a  siphunculus 
or  tube,  which  extends  to  the  remotest  cell.  The 
animal  is  of  the  nature  of  the  sepia,  and  occupies 
the  outer  receptacle  of  the  shell ;  it  maintains  a 
connexion  with  the  inner  chambers  by  means  of  a 
membranous  tube  which  lines  the  siphuncle.  The 
chambers  are  internal  air-cells,  and  the  creature  has 
the  power  of  filling  the  siphuncle  only,  with  a  fluid 
secreted  for  the  purpose,  and  of  exhausting  it ;  the 
difference  thus  effected  in  the  specific  gravity  of  the 
animal  and  its  shell  enables  the  nautilus  to  sink  or 
swim  at  pleasure.  If,  therefore,  you  imagine  a 
cuttle-fish  placed  in  the  outer  chamber  of  a  nau- 
tilus, with  its  arms  extended,  and  having  a  tube 
connected  with  the  siphunculus,  but  neither  ink-bag 
nor  bone,  these  being  unnecessary  to  an  animal 
having  the  protection  and  mechanism  of  a  cham- 
bered shell,  you  will  have  a  tolerably  correct  idea 
of  the  recent  nautilus.  The  nautilus  is  essentially 
a  ground-dwelling  animal,  feeding  on  the  marine 
plants  which  grow  at  the  bottom  of  the  sea.  **  Rum- 
phius  states  that  it  creeps  with  the  shell  above,  and 
that  by  means  of  its  tentacula  it  can  make  quick 
progress  along  the  ground."* 

21.     THE     AMMONITE,     OR    CORNU    AMMONIS. 

The  fossils  called  ammonites,  like  the  belemnites, 
also  first  appear  in  the  secondary  formations  ;  or 
more  properly,  no  traces  of  their  remains  have  been 
found  in  the  tertiary  deposits.  The  ammonite,  so 
*  Dr.  Buckland's  Essay. 


§21.  THE  AMMONITE,  OR  CORNU  AMMONIS.  319 

called  from  its  supposed  resemblance  to  the  horn  of 
Jupiter  Ammon,  is  a  fossil  chambered  shell,  coiled 
up  in  the  form  of  a  disk,  bearing  a  close  analogy  to 
the  nautilus,  but  differing  in  the  situation  of  the 
siphuriculus,  and  in  the  septa  by  which  the  interior 
is  divided.      In  the  nautilus  these  partitions  are 
entire,  and  their  section  presents  a  series  of  simple 
curves,  (Tab.  54,  fig.  3 ;)  but  in  the  ammonite  they 
possess  every  variety  of  sinuosity,  and  the  external 
surface  of  the  casts  of  the  ammonites  commonly 
exhibits  markings  resembling  the  outlines  of  deeply 
fringed  foliage;  the  shell  is  also  generally  decorated 
with  flutings,  ribs,  or  tubercles.     The  siphuncle,  or 
syphon,  which  in  the  nautilus  is  central,  is  placed 
at  the  back  of  the  ammonite.     I  have  placed  before 
you  specimens  from  the  Gait  of  Folkstone,  in  which 
the  shell  remains, — from  Watchett,  with  the  internal 
nacreous  coat  only, — while  in  this  common  species 
from  \\hitby  the  shell  is  altogether  wanting,   the 
specimen  being  a  cast  of  the  interior,   formed  of 
argillaceous  iron-stone,  a  state  in  which  these  fossils 
are  frequently  found.    In  some  examples,  the  shells 
and  partitions  of  the  chambers  having  decomposed, 
casts  of  the   cells    have   been    formed,   which   fit 
into  each  other,  and  admit  of  being  put  together, 
so  as  to  show  the  entire  shape  of  the  ammonite. 
Nautili  also  occur  in  this   state  ;    and  in   a  spe- 
cimen, for  which  I  am  indebted  to  Miss  Pearson, 
of  Clapham,  the  series  is  complete  from  the  com- 
mencement to  the  outer  cell.   Nearly  three  hundred 


320  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

kinds  of  ammonites  are  known  in  the  secondary 
formations,  certain  forms  being  restricted  to  par- 
ticular rocks.  Thus,  for  example,  the  chalk  marl  of 
Sussex  abounds  in  two  species,  (Tab.  53,  figs.  7, 9,) 
which  either  are  very  rare,  or  do  not  occur  in  the 
white  chalk  above,  or  in  the  gait  below;  and  in 
every  locality  of  the  marl  in  England,  and  on  the 
continent,  these  species  are  found.  But  I  must 
again  refer  you  to  Dr.  Buckland's  Bridgewater 
Essay  for  much  important  and  interesting  informa- 
tion on  these  subjects.  I  will  add  but  one  remark ; 
the  membranous  tube  of  the  siphuncle  sometimes 
occurs  in  a  fossil  state;  as  may  be  seen  in  this 
ammonite  from  the  chalk-marl  near  Lewes,  which 
retains  a  large  portion  of  the  siphuncle ;  the  black 
substance  of  these  tubes  has  been  analysed,  and 
found  to  consist  of  animal  membrane,  permeated 
by  carbonate  of  lime.  Dr.  Prout  is  of  opinion  that 
the  black  colour  has  originated  from  decomposition  ; 
the  oxygen  and  hydrogen  of  the  animal  membrane 
having  escaped,  and  carbon  been  evolved,  as  happens 
when  vegetable  matter  is  converted  into  coal,  under 
the  process  of  mineralization.  The  lime  has  taken 
the  place  of  the  oxygen  and  hydrogen,  which  ex- 
isted in  the  pipe  before  decomposition.* 

Ammonites  vary  in  size  from  a  few  lines  to  twelve 

or  fourteen  feet  in  circumference ;  at  low  water  on 

those  parts  of  the  Sussex  coast  where  the   chalk 

forms  the  base  of  the  shore,  enormous  specimens 

*  Bridgewater  Essay,  p.  352. 


§  23.  TURRILITES.  321 

are  often  seen  imbedded.  In  some  limestone  dis- 
tricts, the  marble  is  almost  wholly  composed  of 
ammonites,  as  in  this  polished  slab  from  Somerset- 
shire, which  is  adorned  with  most  beautiful  and 
varied  sections  of  the  inclosed  shells. 

22.  TURRILITE,  HAMITE,  &c. — Baculitcs,  turri- 
lites,  hamites,  and  other  genera  of  nmltilocular 
shells,  abound  in  the  chalk  marl,  gait,  and  Shanklin 
sand.  The  turrilite  (Tab.  53,  fig.  2),  may  be  de- 
scribed as  an  ammonite  twisted  in  a  spiral,  instead 
of  a  discoidal  form :  and  the  hamite  (Tab.  53,  fig.  6), 
as  a  similar  structure  in  the  shape  of  a  hook,  coiled 
up  at  the  smaller  extremity.  These  shells  some- 
times attain  a  large  size ;  the  turrilite  before  you, 
which  is  the  finest  example  known,  would  if  perfect 
exceed  two  feet  in  length  ;  it  possesses  traces  of 
the  siphuncle.  Hamites  of  gigantic  proportions 
have  been  found  in  the  Shanklin  sand  of  Kent,  by 
Mr.  Hills,  the  intelligent  and  indefatigable  curator 
of  the  Chichester  Museum.  The  first  specimens  of 
turrilites,  hamites,  and  scaphites,  from  the  British 
strata,  were  discovered  in  my  early  researches,  in 
Hamsey  marl-pits,  near  Lewes.*  The  scaphite  is 
of  a  boat-like  form ;  but  I  must  forbear  entering 
on  its  description,  as  well  as  on  that  of  many  other 
multilocular  shells,  hundreds  of  which  are  micro- 
scopic, and  sometimes  form  entire  layers  in  the 
chalk. 

23.  SPIROLINITES. — There  is  however  one  genus 
*  Sowerby's  Mineral  Conchology,  vol.  i.  Tab.  18. 

y 


322 


THE  WOJJDERS  OF  GEOLOGY. 


LECT.  IV. 


which  I  cannot  pass  over  without  remark ;  it  is 
called,  from  the  disposition  of  its  chambers,  the 
spirolinite,  and  resembles  the  common  nautilus 
spirula,  the  crozier-shell  of  collectors,  except  that 
the  coils,  which  in  the  recent  shell  are  separate, 
are  in  this  fossil  in  close  apposition.  Several  species 


TAB.  55. — SPIROLINITES  IN  FLINT. 
(By  the  Marquit  of  Northampton,  P.R.S.) 

Fig.  1.  Spirolinites  Lyellii.     Fig.  2.  S.  Murchisom. 

previously  unknown  in  the  chalk,  were  discovered 
by  the  Marquis  of  Northampton,  P.R.S.  some  years 
since,  in  the  pebbles  on  the  Brighton  shores ;  and 


§23. 


SPIROLINITES. 


323 


in  flints  from  the  chalk  at  Kemp-town,  and  other 
places :  these  minute  but  most  interesting  objects 
having  escaped  the  notice  of  less  accurate  and  in- 
telligent observers.  My  son  also  has  collected 


TAB.  56.— SPIROLINITES  IN  FLINTS. 
(By  the  Marquis  of  Northampton,  P.R.S.  $c.) 

Fig.  1.  Spirolinites  Stokesii.    2.   S.  Mantellii.    3.   S.  Lyellii. 
4.  S.  Comptoni. 

several  specimens  from  the  chalk  and  flints  near 
Chichester.  I  have  great  pleasure  in  laying  before 
you  enlarged  drawings,  by  his  lordship,  of  four 

Y2 


324  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

species ;  the  smaller  figures  indicate  the  size  of  the 
originals.* 

24.  INFUSORIA  IN  FLINT. — Among  the  almost 
endless  diversity  of  forms  in  which  those  atoms  of 

*  Note  on  the  Sussex  spirolinites,  by  the  Marquis  of  North- 
ampton : — 

"  I  willingly  comply  with  your  desire  to  communicate  a  short 
note  on  the  Sussex  spirolinites,  one  species  of  which  you  have 
been  pleased  to  distinguish  by  my  name.  I  have  found  these  fossils 
in  flint  at  Brighton,  Kemp-town,  Rottingdean,  Lewes,  Hastings, 
Steyning,  Chichester,  West  Stoke,  and  in  the  Isle  of  Wight ; 
and  one  specimen  in  France.  I  have  discovered  about  two 
hundred  of  these  minute  chambered  shells  in  flint,  but  only  two 
in  chalk.  Some  of  the  microscopic  bodies  extricated  from  the 
chalk  by  Mr.  Lonsdale,  I  am  inclined  to  think  are  spirolinites, 
but  others  are  foraminifera.  I  have  seen,  as  I  believe,  minute 
nummulites  in  the  Sussex  flint.  The  spirolinites  which  I  have 
collected  constitute  four  distinct  species.  1.  The  one  to  which 
you  have  been  pleased  to  give  the  appellation  of  S.  Comptoni. 
2.  Spirolinites  Lyellii,  distinguished  by  the  horizontal  chambers, 
one  above  the  other,  in  the  coiled  portion.  3.  S.  Stokesii,  which 
I  name  after  our  friend  Charles  Stokes,  Esq. ;  and  this  name 
has  the  further  advantage  of  pointing  out  the  locality,  West 
Stoke,  near  Chichester,  from  which  I  obtained  this  unique 
specimen,  and  where  other  spirolinites  abound.  The  fourth 
vou  must  allow  me  to  designate  S.  MantelliL  The  distinctive 
characters  of  these  species  are  too  obvious  to  require  detailed 
description.  The  transverse  chambers  in  S.  Lyellii  (Tab.  55, 
fig.  1,  and  Tab.  56,  fig.  3,)  are  a  striking  peculiarity  of  structure  ; 
in  the  specimen  from  France  (Tab.  55,  fig.  1),  there  appear 
indications  of  a  siphuncle  in  the  straight  prolongation.  I  am 
inclined  to  believe  that  there  are  other  species  in  my  collection, 
but  the  irregularity  in  the  fractured  sections  of  these  minute 
chambered  shells,  renders  it  difficult  to  arrive  at  accurate  con- 
clusions on  this  point. 

"  Castle  Ashby,  January  1,  1838."  "  NORTHAMPTON." 


§  24.  INFUSORIA  IN  FLINT.  325 

animal  existence,  the  infusoria  (so  called  because 
numerous  species  abound  in  vegetable  infusions) 
appear,  many,  like  the  cypris  of  which  we  have 
already  spoken,  possess  shields  or  coverings,  some 
of  which  are  ferruginous,  others  calcareous,  and 
many  silicious  ;  the  yellow  film  seen  on  the  surface 
of  stagnant  water  is  made  up  of  these  animals. 
The  infusoria  belong  to  many  distinct  families,  some 
having  a  complex  organization,  with  a  nervous, 
muscular,  and  circulating  system,  and  digestive 
organs  highly  developed.  As  I  shall  revert  to  this 
subject  in  another  lecture,  I  now  only  wish  to  call 
your  attention  to  the  remarkable  fact,  that  the  sili- 
cious cases,  or  skeletons,  of  this  class  of  beings, 
have  been  discovered  in  a  fossil  state ;  and  that 
some  deposits,  for  instance  the  tripoli  of  Bilin  in 
Bohemia,  consist  almost  entirely  of  the  silicified 
remains  of  infusoria,  of  a  species  so  minute,  that  a 
cubic  inch  of  stone,  weighing  220  grains,  contains 
upwards  of  41  thousand  millions  of  these  skeletons.* 
The  distinguished  naturalist,  Ehrenberg,  to  whom 
we  are  indebted  for  this  wonderful  discovery,  has 
also  detected  the  remains  of  these  animalculae  in 
chalk-flints,  semi-opal,  and  other  silicious  substances; 
and  the  Rev.  I.  B.  Reade,  of  Peckham,f  has  observed 
in  the  flints  of  Surrey,  shields  of  gaillonella,  a  form 
of  infusorial  animal  well  known  to  microscopic 

*  See  a  translation  of  Ehrenberg's  Observations  on  these 
discoveries,  in  Taylor's  Scientific  Memoirs,  Part  III. 
f  Appendix  H. 


320  THE  WONDFRS  OF  GEOLOGY.  LECT.  IV. 

observers.  I  shall  hereafter  place  before  you  repre- 
sentations of  several  of  these  objects ;  it  is  sufficient 
for  the  present  to  have  stated  the  fact,  that  entire 
masses  of  flint  are  composed  of  the  fossilized  remains 
of  beings,  as  wonderful  in  their  structure  and  or- 
ganization, as  any  of  the  colossal  forms  of  animal 
existence.*  Some  kinds  of  opal  appear  to  have 
been  formed  of  the  dissolved  silicious  skeletons  of 
these  animalcules,  and  the  more  durable  forms  are 
seen  preserved  in  it  like  insects  in  amber. -j- 

25.  CRUSTACEA  OF  THE  CHALK.  —  Species  of 
several  genera  of  Crustacea  have  been  obtained  from 
the  Sussex  chalk;  in  some  examples  I  have  suc- 
ceeded in  removing  the  surrounding  stone,  and 
exposing  the  filiform  antennae,  the  abdominal  seg- 
ments, and  the  tails  of  astacida.  In  the  gait,  the 
Crustacea  hitherto  discovered  belong  to  very  small 
species.  I  have  obtained  from  Ringmer,  near 
Lewes,  specimens  which,  in  the  opinion  of  Dr.  Leach, 
are  extinct  forms,  related  to  Indian  genera.  In  the 
Speeton  clay  of  Yorkshire,  Professor  Phillips  has 
discovered  several  beautiful  species  of  astacus.J 
The  Shanklin  sands  of  Kent  and  Dorsetshire  have 

*  The  vegetable  kingdom  presents  us  with  forms  equally 
minute.  The  red  colour  occasionally  observable  in  the  snow 
at  Baffin's  Bay,  is  occasioned  by  a  species  of  fungus  (urcdo 
nivalis),  a  full  grown  individual  of  which  is  but  l-1600th  of  an 
inch  in  diameter ;  each  square  inch  of  the  snow  is  therefore 
covered  by  two  millions  five  hundred  thousand  fungi. — Batter. 

t  LyelFs  Elements  of  Geology. 

J  Astacus,  cray-fish. 


§26.         CRUSTACEA  OP  THE  CHALK.          327 

yielded  a  few  crustacean  remains.  In  the  limestone 
of  St.  Peter's  Mountain,  claws  of  a  small  kind  of 
crab  are  frequently  discovered  (Tab.  57),  but  no 


TAB.  57.— CLAWS  OP  A  CRAB  IN  LIMESTOXE,  FROM  MAESTRICHT. 
(Pagurui  Faujatii.J 

other  vestiges  of  the  animal.  Faujas  St.  Fond,  and 
Latreille,  have  very  ingeniously  explained  this  fact, 
by  showing  that  the  claws  belonged  to  a  parasitical 
species,  which  like  the  common  hermit-crab  of  our 
seas,  had  the  body  covered  by  a  delicate  membrane, 
the  claws  alone  having  a  shelly  casej  hence  the 
latter  would  be  found  in  a  fossil  state,  while  of  the 
other  parts  of  the  animal  no  traces  would  remain. 

26.  FISHES  OF  THE  CHALK  —  SHARKS.  —  The 
fossil  fishes  of  the  chalk  were  known  only  by  the 
teeth,  which  abound  in  almost  every  quarry,  until 
my  researches  in  the  chalk-pits  around  Lewes 


328  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

brought  to  light  the  extraordinary  specimens  before 
you,  and  showed  how  such  delicate  remains  could 
be  developed.  The  teeth  for  the  most  part  belong 
to  fishes  allied  to  the  shark;  a  family  which  in  the 
ancient,  as  in  the  modern  seas,  appears  to  have 
been  confined  by  no  geographical  limits.  Professor 
Agassiz,  by  whose  genius  and  perseverance  this  de- 
partment of  palaeontology  has  been  so  successfully 
elucidated,  has  proposed  a  classification  of  fishes, 
founded  upon  the  peculiar  structure  of  the  scales — 
an  arrangement  of  great  utility  to  the  geologist, 
since  the  mutilated  state  in  which  ichthyolites  so 
frequently  occur,  render  futile  the  attempt  to  place 
them  in  the  existing  orders  and  genera.* 

The  teeth  of  sharks,  particularly  those  of  the 
genus  lamna  (Tab.  58,  figs.  2,4),  are  very  common 
in  the  chalk,  and  occur  occasionally  in  the  flint; 
they  possess  a  high  polish,  are  in  an  excellent  state 
of  preservation,  and  are  always  single,  arising  from 
the  cartilaginous  nature  of  the  jaws  of  the  original. 
These  examples  of  the  recent  shark  show  the  number 
and  variety  of  the  teeth  in  an  individual ;  by  the 
decomposition  of  the  jaw  the  teeth  would  be  sepa- 
rated and  drifted  by  the  water,  and  therefore,  in  a 
fossil  state,  seldom  exhibit  any  traces  of  their  ori- 
ginal position.  It  may,  however,  happen,  that  jaws 
with  teeth  will  hereafter  be  discovered,  for  vertebrae, 
fin-bones,  and  even  the  shagreen  skin  of  sharks,  are 
preserved  in  some  specimens  in  my  collection.  The 
*  See  Appendix  I. ;  and  Dr.  Buckland's  Essay,  p.  268. 


§  20.  FISHES  OF  THE  CHALK.  329 

broad  rugous  teeth  (fig.  6)  are  sometimes  found  in 
groups  of  twenty  or  thirty ;  they  belong  to  a  fish 
allied  to  the  shark,  in  which  the  mouth  was  covered 


TAB.  58. — TEETH  OF  FISHES  ALLIED  TO  THE  SHARK,  FROM  THE 
SUSSEX  CHALK. 

Fig.  1.  Notidanus  microdon.  2.  Lamna  Mantellii.  3.  Galeus  pristo- 
dontus.  4.  Lamna  appendiculata.  5.  Ptychodus  altior.  6.  Ptychodus 
decurrens. 


with  these  bony  processes,  like  a  tessellated  pave- 
ment. The  spines,  fin-bones,  or  rays  of  fishes,  also 
occur  in  the  chalk ;  and  I  have  one  splendid  spe- 
cimen, in  which  even  the  tendinous  expansion  of 


330  THE  WONDERS  OF  GEOLOGY.  LECT.  IV- 

the  muscle  that  moved  the  fin-bone  is  preserved.* 
Some  of  those  in  .my  cabinet  belong  to  the  same 
genus  as  the  dog-fish  of  our  coast  (spinax  acan- 
thias),  which  has  a  curved  spine  in  front  of  the 
dorsal  fin ;  I  place  before  you  a  recent  and  fossil 
spine,  to  show  their  analogy.  The  mandible,  or 


TAE.  59.— MANDIBLE  OF  A  SPECIES  OF  CHIMERA,  FROM  THE  CHALK 
NEAR  LEWES. 

(One-half  the  natural  size.) 

jaw-bone,  of  a  very  curious  fish  (the  chimera)  was 
one  of  my  earliest  discoveries  in  Hamsey  marl-pit, 
and  I  have  since  found  examples  in  the  chalk  of 
Lewes ;  other  species  have  been  discovered  in  the 
green  sand  of  Kent,  by  Mr.  Bensted,  and  in  the 
Kimmeridge  clay,  by  Sir  Philip  Egerton.-f- 

The  remains  of  large  fishes,  belonging  to  that 
division  called  by  Agassiz,  sauroid,  from  their  com- 

*  Fossils  of  the  South  Downs,  Tab.  xxxix. 

f  The  nature  of  these  curious  relics  remained  unknown,  till 
Dr.  Buckland  ascertained  that  they  are  the  mandibles  of  several 
extinct  species  of  chimera. 


§  27.  FOSSIL  SALMON,  OR  SMELT.  331 

bining  in  their  structure  certain  characters  of  rep- 
tiles, have  been  found  in  the  chalk  and  green  sand 
of  Sussex  and  Kent.  They  consist  of  large,  conical, 
striated  teeth,  bearing  a  resemblance  to  those  of 
crocodiles,  with  which  they  were  formerly  con- 
founded. I  have  several  from  the  white  chalk  near 
Lewes ;  Mr.  Bensted  has  discovered  others  in  the 
Kentish  rag,  and  Mr.  Rose,  in  the  gait  of  Cam- 
bridge. 

27.  FOSSIL  SALMON,  OR  SMELT. — But  the  most 
remarkable  ichthyolites  of  the  chalk,  are  the  fishes 
belonging  to  the  salmon  family  (salmonidce),  and 
closely  related  to  the  smelt  (osmerus).  Many  years 
since,  I  succeeded  in  extricating  from  the  chalk  the 
extraordinary  specimen  before  you.* 

The  length  of  the  fish  is  nine  inches,  and  it 
stands  nearly  six  inches  in  relief;  the  back  is  still 
attached  to  the  chalk,  and  the  dorsal  fin  is  exposed. 
There  are  other  examples  of  the  same  species  in  my 
cabinet,  which  are  almost  equally  perfect.  These 
ichthyolites  were  obtained  from  the  quarries  in  the 
immediate  vicinity  of  Lewes,  during  my  residence 
in  that  town.  It  is  clear  that  the  chalk  must  have 
surrounded  the  fishes  while  they  were  alive  and  in 
actual  progression,  and  by  suddenly  consolidating, 
preserved  their  forms  unaltered ;  for  the  body  is 
round  and  uncompressed,  the  mouth  open,  and  the 

*  A  beautiful  lithograph  of  this  fossil,  by  Mr.  Pollard, 
forms  the  frontispiece  of  the  Catalogue  of  the  ManteUian 
Museum. 


332  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

fins  and  gills  are  expanded.  Even  to  those  whose 
curiosity  has  not  previously  been  awakened  to  geo- 
logical inquiries,  the  examination  of  these  petrified 
inhabitants  of  the  ocean  cannot  fail  to  excite  deep 
interest ;  and  I  have  seen  the  man  of  fashion,  as 
well  as  the  philosopher,  gaze  in  mute  astonishment 
on  these  "  relics  of  a  former  world." 

28.  MACROPOMA,  AND  OTHER  FISHES. — I  have 
already  mentioned  that  the  capsule  of  the  eye  re- 
mains in  many  specimens  ;  this  is  particularly  the 
case  with  those  fishes  (beryx}  which  have  some  re- 
semblance to  the  dory  (Tabs.  63,  64).  In  a  sauroid 
fish,  named  macropoma  by  M.  Agassiz,  the  mem- 
branes of  the  stomach  are  invariably  preserved ; 
this  fish  (Tab.  61),  independently  of  the  fact  just 
stated,  is  extremely  remarkable  in  its  organization. 
The  operculum  of  the  gills  is  very  large,  and  the 
scales  are  studded  with  hollow  tubes.  In  many 
recent  fishes,  there  is  a  row  of  tubular  scales, 
forming  what  is  called  the  lateral  line,  through 
which  flows  a  fluid  that  lubricates  the  surface  of 
the  body;  in  the  macropoma,  every  scale  appears 
to  have  possessed  such  a  mechanism. 

Many  of  the  most  interesting  chalk  ichthyolites 
in  my  museum  are  figured  by  M.  Agassiz,  in  his 
important  and  splendid  work — "  Recherches  sur 
les  Poissons  Fossiles"  I  now  place  before  you 
restored  figures  of  seven  species ;  for  comparative 
anatomy  enables  us  not  only  to  reconstruct  the 
colossal  mammalia,  and  the  palaeotheria,  but  also  to 


§28. 


FOSSIL  FISHES  FROM  LEWES. 


333 


TAB.  60.— Fig.  1.  OSMEROIDES  MANTELLII.    Length  12  inches.    From 

Lewes  Chalk-pits. 
Fig.  2.  ACROGNATHUS  Boops.    Natural  size.     Unique.    From  Lewes. 


334 


THE  WONDERS  OF  GEOLOGY.  LECT.  IV 


TAB.  61.— Fig.  1.  AULOLEPIS  TYPUS.— Length  6  inches.  Unique.  From 
Clayton  Chalk-pit.  Fig.  2.  MACROPOMA  MANTELLII. — Length  24 
inches.  From  the  chalk  quarries  near  Lewes. 


§28. 


FOSSIL  FISH  FROM  LEWES. 


335 


TAB.  62. — DEB.CETIS  ELONGATUS. — Length  16  inches.    From  Lewes. 

This  species  occurs  abundantly  in  the  chalk  at  Preston,  near  Brighton. 
The  outline  represents  the  skeleton,  from  a  specimen  in  my  museum ; 
the  only  instance  in  which  the  skull  remains. 


336 


THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 


TAB.  63.— BERYX  RADIANS.     Length  7  inches.     From  the  chalk-marl, 
near  Lewes. 


This  species  is  generally  found  in  the  chalk-marl :  specimens  have  been 
collected  at  Clayton,  Steyning,  and  Arundel,  in  Sussex. 


§23. 


FOSSIL  FISH  FROM  LEWES. 


337 


TAB.  64. — BERYX  LEWESIEXSIS.    Length  12  inches.    From  Lewes 
chalk-quarries. 

This  is  the  most  abundant  of  the  Sussex  ichthyolites ;  and  is  called 
Johnny  Dory  by  the  workmen.  Detached  scales  are  very  frequent  in  the 
chalk  of  the  South  Downs,  and  also  in  that  of  Kent  and  Surrey.  Some 
line  specimens  of  this  species  have  recently  been  found  in  the  chalk  of 
Chatham  and  Maidstone. 


338  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

restore,  with  all  the  lineaments  of  life,  the  fishes 
which  lived  and  died  in  the  seas  of  the  ancient 
world.  These  restorations  have  been  drawn  with 
great  care  by  an  eminent  artist,  M.  Dinkel,  of 
Munich. 

The  fossil  fishes  discovered  in  the  South  Downs 
amount  to  upwards  of  forty  species ;  and  there  are 
several  undescribed  from  the  chalk  of  Kent,  in  the 
splendid  collections  of  ichthyolites  of  Viscount  Cole 
and  Sir  P.  M.  Egerton,  Bart. 

In  the  other  sub-divisions  of  this  formation,  both 
in  England  and  elsewhere,  the  remains  of  fishes 
occur.  The  slates  of  Glaris,  in  Switzerland,  have 
long  been  celebrated  for  their  ichthyolites,  and 
by  these  fossils  M.  Agassiz  was  enabled  to  de- 
termine that  those  strata  belong  to  the  chalk ; 
although  the  schist  in  which  they  are  imbedded, 
as  may  be  seen  in  this  fine  suite  of  specimens 
(collected  and  presented  to  me  by  the  distin- 
guished geologists  above  named),  is  a  compact 
bituminous  slate,  scarcely  to  be  distinguished  from 
some  of  the  most  ancient  of  the  transition  series  ; 
a  character  which  is  attributable  to  the  effects 
of  high  temperature,  as  will  hereafter  be  ex- 
plained. 

In  concluding  this  cursory  review  of  the  fossil 
fishes  of  the  chalk,  it  must  be  remarked  that  all 
these  ichthyolites  are  of  extinct  forms;  and  that 
none  of  the  species,  and  even  but  few  of  the  genera, 
occur  in  more  recent  deposits  j  a  result  in  perfect 


§  29.  REPTILES  OF  THE  CHALK.  339 

accordance  with  that  derived  from  the  examination 
of  the  zoophytes  and  mollusca.* 

29.  REPTILES. — The  remains  of  reptiles  hitherto 
observed  in  the  chalk  are  but  few ;  the  most  im- 
portant is  the  Moscesaurus  ffoffmanni,  of  which 
I  spoke  when  describing  the  Maestricht  deposits. 
The  occurrence  of  the  vertebrae  of  a  reptile  be- 
longing to  the  same  genus,  if  not  species,  in  the 
Lewes  chalk,  and  of  similar  teeth  and  bones  in 
the  equivalents  of  this  formation  in  North  America, 
are  facts  of  great  interest.  Through  the  kindness 
of  Mr.  Charlesworth,  I  have  inspected  portions  of 
a  large  jaw  with  teeth  from  the  Norfolk  chalk, 
which  bear  a  resemblance  to  those  of  the  mosae- 
saurus;  but  the  symmetrical,  conical  form  of  the 
teeth,  and  other  characters,  show  that  they  belong 
either  to  an  unknown  reptile,  or  to  a  sauroid  fish. 
Bones  of  turtles  are  found  in  the  white  chalk  of 
Sussex,  and  abundantly  in  the  limestone  of  St. 
Peter's  Mountain,  and  in  the  slate  of  Glaris ;  they 
belong  to  marine  species.  I  have  a  mandible  of  a 
turtle  from  the  Lewes  chalk,  which  is  figured  by 
Dr.  Buckland  ;  f  and  a  femur  from  Kent,  dis- 
covered by  Mr.  Bensted.  Teeth  of  crocodiles, 
from  the  chalk  of  Meudon,  are  mentioned  by 
Cuvier ;  and  very  recently  a  specimen  containing 
the  vertebral  column,  ribs,  and  pelvis  of  a  small 
lizard,  in  a  beautiful  state  of  preservation,  was 

*  See  Appendix  K. 

t  Bridgevvater  Essay,  Plate  44,  fig.  3. 

z2 


340  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

found  in  a  chalk-pit  near  Chatham,  and  is  in  the 
possession  of  Sir  P.  M.  Egerton. 

30.  REVIEW  OF  THE  CHALK  FORMATION. — The 
characters   of  the  chalk  formation,   as  shown    by 
these  investigations,  are  those  of  a  vast  oceanic 
basin,  filled  with  the  debris  thrown  down  by  its 
waters,  and  which  enveloped  the  remains  of  its  in- 
habitants ;  arenaceous  beds  prevailing  in  the  lower- 
most— argillaceous  in  the  middle — and  cretaceous 
in  the  upper  division  of  the  series.     Intrusions  of 
thermal  streams  appear  to  have  been  abundant  at 
certain  periods ;  and  the  proofs  are  incontrovertible, 
that  throughout  the  entire  epoch  of  its  formation, 
its  waters  swarmed  with  living  beings  of  the  various 
orders  of  marine  existence;   all,  or  almost  all,  the 
species  being  now  extinct.     The  fuel  show  that  it 
possessed  a  marine  vegetation ;    and   the   drifted 
wood,  fir-cones,  stems,  and  leaves,  that  its  shores 
were   bounded  by  dry  land  clothed  with  forests  ; 
the  fossil  reptiles  also  aiford  additional  confirmation 
of  this  inference. 

31.  GEOLOGY  OF   THE   SOUTH-EAST   OF   ENG- 
LAND.— From  this  survey  of  the  marine  formation 
of  the  chalk,  we  turn  to  the  remarkable  fluviatile 
deposits,  of  which  the  basin  of  the  cretaceous  ocean, 
in  the  south-east  of  England,  was  composed  ;    in 
other  countries,  as  I  shall  again  have  occasion  to 
remark,  that  basin  was  formed  of  the  oolite  and 
other  marine  strata.     It  will  now  be  necessarv  to 
offer   a   few  observations  on   the   geology  of  the 


§31.       GEOLOGY  OF  THE  SOUTH-EAST  OF  ENGLAND.       341 

district  in  which  the  beds  of  the  wealden  are  so 
largely  developed. 

The  strata  of  the  south-east  of  England  con- 
stitute three  principal  groups.  The  first  consists 
of  the  tertiary  sands,  clays,  and  gravel,  described 
in  the  previous  lecture,  which  occupy  depressions 
of  the  chalk.  The  second  is  the  chalk,  (including 
under  this  term  the  white  chalk,  gait,  and  green 
sands,)  which  forms  the  most  striking  feature  in 
the  physical  geography  of  the  country.  The  upper 
division  of  the  cretaceous  formation  constitutes  the 
South  Downs,  which  from  the  bold  promontory  of 
Beachy-head,  traverse  the  county  of  Sussex  from 
east  to  west,  and  pass  by  Hampshire  into  Surrey. 
From  Godalming  the  chalk  hills  extend  by  Godstone 
into  Kent,  where  the  range  is  called  the  North 
Downs,  and  terminate  in  the  cliffs  of  Dover.  The 
lowermost  member  of  the  chalk,  the  Shanklin  sand, 
appears  as  a  chain  of  hills  of  very  irregular  elevation, 
which  skirts  the  escarpments  of  the  chalk  downs, 
the  gait  constituting  a  valley  between  them.  The 
third  group  is  spread  over  the  area  between  the 
North  and  South  Downs ;  the  most  elevated  masses 
forming  a  range  called  the  Forest-ridge,  which 
traverses  the  district  in  a  direction  nearly  east  and 
west,  and  is  composed  of  alternations  of  sandstone, 
sands,  shales,  and  clays,  with  a  deep  valley  on  each 
Hank,  called  the  weald;  hence  the  geological  de- 
signation of  the  whole  series.  From  the  central 
ridge  of  the  wealden,  which  varies  in  height  from 


342  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

400  to  800  feet,  the  strata  diverge  on  each  side 
towards  the  Downs,  forming  an  anticlinal  axisy  and 
finally  disappear  beneath  the  lowermost  beds  of  the 
chalk.  (  Vide  the  section,  PL  9,  fig.  1.)  There  are 
conclusive  proofs  that  the  wealden  strata  were  ori- 
ginally covered  by  the  chalk,  and  that  their  present 
position  and  appearance  are  attributable  to  changes 
which  have  taken  place  subsequently  to  the  creta- 
ceous epoch ;  the  wealden  having  been  lifted  up 
and  forced  through  the  chalk,  and  thus  effected  the 
partial  destruction  of  that  formation.* 

32.  GEOLOGICAL  PHENOMENA  BETWEEN  LON- 
DON AND  BRIGHTON.  —  The  direct  roads  from 
London  to  Brighton  pass  over  the  whole  series  of 
deposits  comprised  in  the  above  sketch,  as  well  as 
those  described  in  the  first  lecture.  Proceeding 
from  the  Thames,  the  observer  successively  tra- 
verses the  modern  silt  of  the  river  —  the  ancient 
alluvium,  containing  remains  of  elephants  and  other 
large  mammalia — and  if  he  proceed  by  Reigate,  his 
road,  at  Clapham  and  Tooting,  lies  over  beds  of  clay 
and  gravel,  which  are  part  of  the  ancient  shores 
of  the  London  basin.  At  Suttoii  he  ascends  the 
chalk  hills  of  Surrey,  and  travels  along  elevated 
masses  of  the  ancient  ocean-bed  just  described. 
Arriving  at  the  precipitous  southern  escarpment 
of  the  North  Downs,  a  magnificent  landscape,  dis- 
playing the  physical  structure  of  the  weald,  and 
its  varied  and  picturesque  scenery,  suddenly  bursts 

*  See  Geology  of  the  South-East  of  England,  chap.  xi. 


§  32.         GEOLOGICAL  PHENOMENA  NEAR  REIGATE.         343 

upon  his  view.  At  his  feet  lies  the  deep  valley  of 
gait  in  which  Reigate  is  situated,  and  immediately 
beyond  the  town  appears  the  elevated  ridge  of 
Shanklin  sand,  which  stretching  towards  the  west, 
attains  at  Leith-hill  an  altitude  of  one  thousand  feet; 
and  to  the  east  forms  a  line  of  sand-hills,  by  God- 
stone  and  Sevenoaks,  through  Kent,  to  the  sea-shore. 
The  Forest-ridge  occupies  the  middle  region,  ex- 
tending westward  towards  Horsham,  and  eastward 
to  Crowborough-hill,  its  greatest  altitude,  and  from 
thence  to  Hastings,  having  on  each  flank  the  wealds 
of  Kent  and  Sussex  ;  while  in  the  remote  distance, 
the  unbroken  and  undulated  summits  of  the  South 
Downs  appear  like  masses  of  grey  clouds  on  the 
verge  of  the  horizon. 

Pursuing  his  route,  the  observer  passes  through 
Reigate,  along  the  valley  of  gait,  (see  Plate  9,  Sec- 
tion I.  2,)  and  over  the  Shanklin  sands  of  Cockshut- 
hill,  (3,)  and  arrives  at  the  commencement  of  the 
wealden.*  The  weald  clay,  (4,)  containing  beds  of 
fresh-water  limestone,  appears  at  Horley  common  ; 
and  while  in  the  commencement  of  his  journey  the 
roads  were  made  of  broken  chalk- flints,  and  at  Rei- 
gate of  cherty  sandstone,  the  material  here  chiefly 
employed  is  the  bluish-grey  calcareous  rock  of  the 
weald.  At  Crawley,  (5,)  sand  and  sandstone  appear, 
and  the  road  is  composed  of  grit  and  stone,  con- 
taining fluviatile  shells,  bones  and  plants.  Crossing 

*  The  reader  will  be  able  to  follow  this  route  by  referring  to 
the  section,  PL  9,  fig.  1. 


344  THE  WONDERS  OP  GEOLOGY.  LECT.  IV. 

Tilgate  Forest  and  Handcross,  over  a  succession 
of  elevated  ridges  of  sandstone,  and  through  clay 
valleys,  produced  by  alternations  in  the  strata,  he 
descends  from  the  sandstone  ridge  at  Bolney,  near 
Cuckfield,  and  again  journeys  along  a  district  of 
weald  clay  with  fresh-water  limestone  (4-,  on  the  left). 
Shanklin  sand,  like  that  of  Reigate,  reappears  at 
Hickstead  (3,  on  the  left),  and  is  succeeded  by  a 
tract  of  gait  (2,  on  the  left)  ;  and  finally,  entering  a 
vale  of  chalk-marl,  he  reaches  a  defile  in  the  South 
Downs,  through  which  the  road  winds  its  way  to 
Brighton ;  the  traveller  having  in  the  course  of  his 
journey  passed  from  one  chalk  range  to  the  other, 
and  traversed  the  ancient  delta  of  the  wealden. 

33.  THE  WEALDEN.  —  The  tertiary  basin  of 
London  afforded  an  illustration  of  the  process  by 
which  materials  are  accumulated  and  organic  re- 
mains imbedded,  in  an  inland  sea, — that  of  Paris, 
of  marine  and  fresh-water  sediments,  deposited  in 
a  gulf  open  to  the  sea  on  the  one  side,  and  fed  by 
rivers  and  thermal  springs  on  the  other, — the  lacus- 
trine formations  of  Auvergne,  of  the  gradual  pre- 
cipitation of  strata  in  the  tranquil  waters  of  lakes, — 
the  chalk,  of  the  operations  which  have  taken  place 
in  the  profound  abyss  of  an  ocean,  —  while  the 
series  of  deposits  to  which  the  term  wealden  is 
applied,  presents  the  most  striking  example  of  an 
ancient  fluviatile  formation  hitherto  discovered. 
Yet  strange  as  it  may  appear,  although  the  wealden 
strata  are  spread  over  the  whole  area  between  the 


§  33.  THE  WEALDEN.  345 

North  and  South  Downs,  a  tract  of  country  tra- 
versed daily  by  hundreds  of  intelligent  persons  from 
the  metropolis,  their  peculiar  characters  were  en- 
tirely unknown  fifteen  years  ago  ;*  the  whole  group 
being  supposed  by  geologists  to  belong  to  a  series 
of  marine  clays  and  sands  below  the  chalk. -j- 

Before  entering  upon  the  description  of  these 
strata,  I  would  remind  you  of  what  has  been  stated 
in  a  previous  lecture,  of  the  effects  of  rivers,  and 
the  nature  of  modern  fluviatile  deposits  (pp.  39,  40). 
We  found  the  deltas  of  rivers  to  consist  of  clay  (or 
indurated  mud),  alternating  with  beds  of  sand  and 
sandstone  (or  consolidated  sand),  and  containing 
leaves,  branches,  and  trunks  of  trees,  fresh-water 
shells,  works  of  art,  bones  of  man,  and  of  land 

*  "  Until  the  appearance  of  Dr.  Mantell's  works  on  the 
Geology  of  Sussex,  the  peculiar  relations  of  the  sandstones 
and  clays  of  the  interior  of  Kent,  Sussex,  and  Hampshire,  were 
entirely  misunderstood.  No  one  supposed  that  these  immense 
strata  were  altogether  of  a  peculiar  type,  and  interpolated  amid 
the  rest  of  the  marine  formations,  as  a  local  fresh- water  deposit, 
of  which  only  very  faint  traces  can  be  perceived  in  other  parts  of 
England." — Professor  Phillips,  Ency.  Met.  p.  631.  Art.  Geology. 

11  It  was  not  until  the  appearance  of  Dr.  Mantell's  Illus- 
trations of  the  Geology  of  Sussex,  in  1822,  that  the  full  value 
of  the  evidence  which  this  district  affords  was  made  to  appear. 
In  that  work  the  author  clearly  showed  that  the  extraordinary 
remains  which  he  had  discovered  in  the  beds  of  Tilgate  Forest 
must  have  originated  in  a  lake,  or  estuary,  and  have  been  the 
produce  of  a  climate  much  warmer  than  that  which  is  now  en- 
joyed in  England." — Dr.  Fitton's  Geology  of  Hastings,  p.  14. 

f  See  Conybeare  and  Phillips'  Outlines  of  the  Geology  of 
England  and  Wales,  pp.  140,  155. 


346  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

animals,  more  or  less  rolled, — with  boulders  formed 
of  fragments  of  rocks,  transported  by  torrents  from 
the  hills,  or  washed  out  of  the  banks  by  the 
streams.  Let  us  now  suppose  that  by  agencies 
already  explained,  a  river  has  disappeared,  that  the 
sea  also  has  changed  its  place,  and  that  the  bed  and 
the  delta  of  the  river  have  become  dry  land  ;  that 
towns  and  villages  have  been  built  upon  the  con- 
solidated delta,  and  that  its  surface  is  either  clothed 
with  woods  and  forests,  or  under  cultivation.  If 
sections  of  the  strata  were  exposed,  either  by 
natural  or  artificial  means,  and  the  bones  of  men 
and  animals,  with  works  of  art,  and  remains  of 
plants  and  shells,  were  visible  in  the  clay  or  sand- 
stone, such  appearances  would  excite  in  us  no 
surprise,  because  we  are  acquainted  with  the  pro- 
cesses by  which  such  accumulations  are  formed. 
Should  an  inhabitant  of  the  new  country  express 
his  wonder  how  brittle  shells,  delicate  leaves,  and 
bones,  had  become  imbedded  in  the  solid  rock, 
and  if  when  we  stated  the  manner  in  which  those 
changes  had  been  effected,  he  should  not  only  refuse 
his  assent,  but  insist  that  the  shells,  leaves,  and 
bones,  were  merely  accidental  forms  of  the  stone, 
should  we  not  feel  astonished  at  his  ignorance'  and 
prejudice?  yet  not  a  century  since,  and  such  an 
opinion  almost  universally  prevailed,  and  is  even 
still  entertained  by  many !  *  And  farther,  if  our 

*  "At  Hawkhurst,  in  the  weald  of  Kent,  these  stones  (Sussex 
marble)  abound.      They  consist  of  several  laminae,  between 


§  34.  WEALDEN  OF  THE  SUSSEX  COAST.  347 

assumed  personage  admitted  that  the  remains  in 
question  were  fossil  animals  and  vegetables,  but 
asserted  that  they  had  been  entombed  in  the  strata 
by  a  general  deluge  which  had  softened  the  crust 
of  the  earth,  and  engulfed  in  the  sediment  of  its 
waters  the  remains  of  animated  nature, — should  we 
not  reply,  that  as  such  a  catastrophe  must  inevitably 
have  mingled  together  the  remains  of  animals  and 
vegetables,  whether  of  the  land,  the  rivers,  or  the 
seas  —  the  regular  stratification  of  the  materials 
composing  the  delta,  and  the  exclusive  occurrence 
of  land  and  fresh- water  productions,  were  fatal 
to  such  a  supposition,  and  afforded  conclusive  evi- 
dence of  the  correctness  of  our  explanation  of  the 
phenomena  ?  —  by  such  a  train  of  reasoning  the 
fluviatile  nature  of  the  wealden  has  been  deter- 
mined. 

34.  WEALDEN  OF  THE  SUSSEX  COAST. — From 
the  distribution  of  the  wealden  over  the  south-east 
of  England,  instructive  sections  have  been  formed 
by  the  action  of  the  sea  along  the  coast,  between 
Beachy  Head  and  Dover.  From  the  stupendous 
cliffs  of  Beachy  Head  the  chalk  extends  towards 
Southbourn,  where  beds  of  gait,  giauconite,  marl, 

which  grow  shells,  or  rather  half-shells,  having  the  appearance 
of  periwinkles  of  different  magnitudes,  according  to  the  time  of 
their  growth.  These  stones  naturally  grow  in  the  earth,  and 
the  shells  upon  them,  and  are  another  certain  proof  that  shells 
are  generated  in  the  earth,  as  well  as  in  the  sea,  and  that  there  is 
no  necessary  connexion  between  a  shell  and  an  animal."  (!  !)  — 
Natural  History  of  England,  p.  193,  vol.  i.  1759. 


348  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

and  Shanklin-sand,  successively  emerge,  forming 
the  base  of  the  shore,  and  abounding  in  their  cha- 
racteristic marine  fossils.  Passing  over  Pevensey 
Levels,  the  boundary  of  which,  on  the  sea-side,  is 
obscured  by  modern  shingle,  we  arrive  at  Bexhill 
and  Bulverhithe,  and  find  the  cliffs  composed  of 
finely  laminated  sandstone  and  clays  ;  and  those 
of  St.  Leonard,  of  similar  strata,  more  extensively 
developed  :  sands  and  clays  separated  into  very 
thin  laminae,  alternate  with  conglomerates,  indu- 
rated sand-rock,  and  a  fine  sandstone,  of  great 
compactness,  called  grit.  At  Hastings,  sand  and 
clay,  with  interspersions  of  lignite,  laminated  shale, 
grit,  and  sandstone,  constitute  a  long  line  of  high 
cliifs.*  The  general  resemblance  of  these  strata 
to  fluviatile  accumulations  is  most  striking ;  the 
laminated  structure  of  the  clay  and  shales,  the 
constant  intermixture  of  minute  portions  of  lignite, 
the  absence  of  pebbles  and  shingle,  and  the  alter- 
nations of  mud  and  sand,  are  lithological  characters 
constantly  observable  in  river  deposits.  To  the 
west  of  Hastings  a  fine  mass  of  the  strata,  com- 
prising several  layers  of  the  calciferous  grit,  alter- 
nating with  friable  sandstone,  was  formerly  exposed 
on  the  sea  shore,  having  at  a  very  remote  period 

*  See  an  excellent  little  volume  on  these  cliffs,  "  A  Guide  to 
the  Geology  of  Hastings,"  by  W.  H.  Fitton,  Esq.  M.D.  F.R.S.  &c. 
"The  Geology  of  the  South-east  of  England"  contains  a  map, 
sections,  and  full  details  of  the  geological  structure  of  this  in- 
teresting district. 


§35. 


VALE  OF  POUNCEFORD. 


349 

been  separated  from  the  adjacent  cliff.  The  action 
of  the  waves  had  bleached  the  projecting  layers  of 
grit,  from  which  circumstance  the  mass  obtained 
the  name  of  "  White  rock.''  The  late  improvements 


TAB.  65.— WHITE  BOCK,  HASTINGS. 
(Drawn  by  Miss  Jane  Allnutt ) 

a,  Inland  cliff  of  laminated  sandstone  and  clay  ;  b,  Cliff  to  the  east  of 
Hastings.  The  White  rock  is  marked  by  the  flag  on  its  summit ;  it  is 
composed  of  calciferous  grit. 

at  St.  Leonard's  have  removed  all  traces  of  this 
outlying  portion  of  the  Hastings  beds.*  The  nature 
of  the  organic  remains  with  which  the  strata  abound 
will  be  considered  hereafter. 

35.  POUNCEFORD. — In  the  interior  of  the  country, 

the  quarries  opened  along  the  ridges  formed  by  the 

compact  grit,  afford  various  instructive  sections;  and 

the  valleys,  eroded  by  the  streams,  expose  the  shales 

*  Geology  of  the  South-East  of  England,  p.  194. 


350  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

and  laminated  clays.  Pounceford,  on  the  estate  of 
Lord  Ashburnham,  on  the  road  to  Burwash,  in 
Sussex,  presents  several  highly  interesting  sections 
of  the  argillaceous  beds  and  limestones.  Descend- 
ing through  a  defile  in  the  sandstones,  we  arrive  at 
the  bottom  of  a  glen,  along  which  a  rapid  stream, 
that  bursts  out  from  between  the  clay-partings, 
rushes  to  a  distant  and  lower  valley.  On  each  side 
openings  are  made,  to  arrive  at  a  greyish  blue  lime- 
stone abounding  in  shells,  which  is  employed  on  the 
roads,  and  is  also  converted  into  lime  for  agricultural 
purposes.  Where  the  stone  lies  deep,  shafts  are 
sunk  from  the  surface,  and  after  the  extraction  of 
the  limestone,  they  are  deserted  and  filled  up.  This 


TAB.  GGK— CLAY  WITH  SHELLS,  FROM  POUNCEFORD,  SUSSEX. 
a,  Melanopsis  attenuata;   b,  Cyclas  media;   c,  Cyclas  membranacea. 

spot  is  highly  interesting  and  picturesque  ;  incrust- 
ing  springs  issue  from  the  limestone  beds,  and  de- 
posit tufa  on  the  mosses,  equiseta,  and  land-shells : 


§  35.  TILGATE  FOREST.  351 

thousands  of  fossil  shells  are  strewn  over  the  clay 
and  shale ;  and  stems  of  plants,  scales  of  fishes, 
teeth  of  crocodiles,  and  other  remains,  are  seen 
imbedded  in  the  stone;  while  the  banks,  where 
newly  exposed,  exhibit  numberless  laminae  and 
alternations  of  shale,  clay,  and  layers  of  testaceous 
remains.*  In  a  visit  to  this  place  with  my  friend 
Mr.  Lyell,  in  1831,  many  new  species  of  shells  were 
found  in  the  bed  of  the  stream,  having  been  washed 
out  of  the  banks  of  clay  ;  and  we  collected  teeth  of 
crocodiles,  and  bones  of  fresh-water  turtles,  and  of 
other  reptiles.  Several  species  of  cyclas  (a  fresh- 
water bivalve  shell),  and  a  spiral  univalve,  were 
abundant  in  the  clay  (Tab.  66) ;  and  a  muscle, 
(named  Mytilus  Lyellii,  to  commemorate  our  ex- 
cursion, Tab.  77,  fig.  8,)  also  a  fluviatile  species, 
was  found  in  a  mass  of  shale  that  had  fallen  into  the 
rivulet. 

As  the  grit,  or  calciferous  sandstone  of  the 
wealden,  forms  an  excellent  road-material,  the 
quarries  along  the  principal  lines  leading  from  the 
metropolis  to  the  south-eastern  coast,  are  very  nume- 
rous ;  and  those  spread  over  the  area  of  Tilgate 
and  St.  Leonard's  Forests  have  been  extensively 
worked  since  the  increased  communication  between 
London  and  Brighton.  This  district  may  be  de- 
scribed as  bounded  on  the  west  by  the  London 
roads  leading  through  Horsham,  and  on  the  east 

*  See  Fossils  of  Tilgate  Forest,  p.  47.  Geology  of  the  South- 
East  of  England,  p.  22. 


352  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

by  those  which  pass  by  Linfield,  and  Cuckfield;  the 
Crawley  road,  as  previously  mentioned,  traversing 
Tilgate  Forest.  These  localities,  particularly  that 
of  Tilgate,  have  acquired  much  celebrity  for  their 
organic  remains,  from  having  been  the  principal 
sources  whence"  the  specimens  figured  in  my  first 
work  on  the  "  Fossils  of  Tilgate  Forest,"*  were 
derived  ;  but  every  quarry  throughout  the  Forest- 
range,  from  Loxwood  in  western  Sussex,  to  Has- 
tings, will  be  found  to  yield  the  peculiar  fossils  of 
the  wealden  more  or  less  abundantly. 

36.  SUBDIVISION  AND  EXTENT  OF  THE  WEALDEN. 
— The  wealden  may  be  divided  into  several  groups, 
each  characterised  by  the  nature  of  the  strata,  and 
the  prevalence  of  certain  kinds  of  fossils;  but 
throughout  the  whole  series,  the  fluviatile  character 
of  the  formation  is  maintained  :  in  the  lowermost 
part  of  the  series  only  are  there  any  intrusions  of 
a  marine  or  estuary  nature.  Although  it  is  not 
within  the  scope  of  these  lectures  to  enter  upon 
minute  details  of  stratification,  it  will  be  necessary, 
for  the  elucidation  of  the  subject,  to  point  out  the 
principal  subdivisions  of  this  extensive  system  of 
fresh-water  deposits. -j- 

1.  WEALD  CLAY  (the  uppermost  or  latest  deposit}. — Stiff  blue 
clay,  with  septaria,  argillaceous  ironstone,  and  beds  of  shelly 
limestone,  called  Sussex  or  Petworth  marble.  (See  the  sec- 
tion PL  9,  fig.  I.  4.) 

*  See  Fossils  of  Tilgate  Forest,  p.  51. 

f  Geology  of  the  South-East  of  England,  p.  182. 


§  36.  SUBDIVISIONS  OF  THE  WEALDEN.  ,•].",;} 

2.  HASTINGS  BEDS. — Sand  and  sandstones,  with  calciferous  grit, 
or  Tilgate- stone,  alternating  with  clays  and  limestones. 

o.  ASHBURNHAM  BEDS. — Clays,  shales,  and  bluish-grey  lime- 
stones and  sandstones. 

4.  PURBECK  BEDS — Clays,  sandstones,  and  shelly  limestone, 
called  Purbeck  marble.  Limestone,  with  layers  of  vegetable 
mould,  and  trunks  of  trees  in  a  vertical  position — the  petri- 
fied Forest  of  Portland. 

Such  is  the  assemblage  of  deposits  which  the 
term  wealden,  first  employed  in  this  acceptation  by 
Mr.  Martin,*  is  intended  to  denote.  Clays,  and 
limestone  almost  wholly  composed  of  fresh-water 
snail-shells,  occupy  the  uppermost  place  in  the 
series ;  sand  and  sandstones,  with  shales  and  lignite, 
prevail  in  the  middle ;  while  in  the  lowermost, 
argillaceous  beds,  with  shelly  marbles  or  limestones, 
again  appear ;  and,  buried  beneath  the  whole,  is  a 
petrified  forest,  in  which  the  trees  are  still  standing, 
and  the  vegetable  mould  undisturbed  !  The  upper 
clay-beds  and  marbles  form  the  deep  valleys  or 
wealds  of  Kent  and  Sussex — the  middle  series  con- 
stitutes the  forest-ridge.  The  Purbeck  are  ob- 
scurely seen  in  some  of  the  deepest  valleys  of 
eastern  Sussex;  they  emerge  on  the  Dorsetshire 
coast,  form  the  island  or  peninsula  whose  name  they 
bear,  and  surmount  the  northern  brow  of  the  Isle 
of  Portland.  At  the  back  of  the  Isle  of  Wight, 
the  wealden  beds  appear  beneath  the  Shanklin 
sands ;  and  their  characteristic  fossils  are  conti- 
nually washed  up  on  the  shore  at  Brook-point* 

*  Martin's  Geology  of  Western  Sussex. 
A  A 


354  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

Dr.  Fitton*  has  traced  the  wealden  beds,  or  rather 
the  lowermost  division,  the  Purbeck,  in  the  vale  of 
Wardour,  which  is  a  valley  of  denudation,  in  the 
south  of  Wiltshire,  like  that  of  the  South-east  of 
England,  on  a  small  scale.  In  this  valley  the  vari- 
ous members  of  the  chalk  occur  in  their  regular 
order  of  superposition,  resting  on  clay  and  Purbeck 
limestone,  and  having  the  Portland  stone  beneath. -f- 
In  France,  on  the  coast  of  the  Lower  Boulonnais, 
and  in  the  valley  of  Bray  near  Beauvais,  strata  of 
a  like  character  are  observable ;  the  Sussex  marble 
(lumachelle-a-paludines})  and  a  fern  peculiar  to  the 
wealden,  have  been  discovered  by  M.  Graves  of 
Beauvais,  to  whom  I  am  indebted  for  specimens. 
It  is  probable  that  the  wealden  may  have  extended 
over  a  still  larger  area,  for  the  same  fossil  plant 
(lonchopteris  Mantellii,  Tab.  73)  has  been  found  in 
strata  beneath  the  green-sand,  in  Sweden,  by  Pro- 
fessor Nillson,  who  informed  me  that  several  of 
the  fossil  plants  from  Tilgate  Forest  were  analo- 
gous to  specimens  he  had  collected  in  the  little 
island  of  Bornholm,  off  the  Danish  coast.  Without 
implicitly  relying  upon  these  observations,  the 
wealden  may  be  considered  as  covering  an  area 
200  miles  in  length  from  west  to  east,  and  220 
miles  from  north-west  to  south-east ;  an  extent  but 
little  exceeding  the  delta  of  the  Ganges  or  of  the 

»  Consult  Dr.  Fitton's  Memoir  "  On  the  Beds  below  the 
Chalk;"  Geological  Transactions,  1837. 
f  Ibid.  p.  424. 


§  37.  QUARRIES  OF  TILGATE  FOREST.  355 

Mississippi,  and  surpassed  by  that  of  the  Quorra, 
which  forms  a  surface  of  25,000  square  miles,  being 
equal  to  the  half  of  England.  The  total  thickness 
of  the  wealden  deposits  averages  about  2000  feet.* 
37.  QUARRIES  OF  TILGATE  FOREST. — The  quar- 
ries of  Tilgate  Forest,  where  the  calciferous  grit  is 
worked,  present  the  following  series  of  strata  : — 

1.  Uppermost.     Loam  or  clay — from  one,  to  five  or  six  feet  in 
depth.     Destitute  of  fossils. 

2.  Sandstone — friable,  of  various  shades  of  fawn,  yellow,  and 
ferruginous  colour ;  in  laminae,  or  thin  layers,  occasionally 
containing  organic  remains  and  pebbles, — eight  feet  thick. 

3.  Calciferous  grit,  or   Tilgale   stone — a  very  fine   sandstone, 
formed  of  sand  cemented  together  by  calcareous  spar ;  it 
occurs  in  large  masses  of  a  concretional  form,  imbedded  in 
soft  sandstone.      This  grit  has  evidently  been  formed  of 
loose  sand,  by  the  percolation  of  water  charged  with  calca- 
reous matter ;  it  abounds  in  bones  and  teeth  of  reptiles ; 
stems  and  leaves  of  plants ;  shells,  &c. 

4.  Sandstone,  with  concretionary  masses  of  grit  and  conglo- 
merate   formed  of   rolled  pebbles   of   sandstone,   jasper, 
quartz,  indurated  clay,  bones  and  teeth  of  reptiles,  and  of 
fishes  ;  rolled  masses  of  the  grit  and  sandstone  are  found  in 
this  conglomerate;  the  organic  remains  which  it  contains 
are  generally  much  water-worn. 

5.  Blue  clay  and  marl — depth  unknown. 

Such  is  the  usual  character  of  the  strata  exposed 

in  the  quarries  around  Bolney,  Cuckfield,  Linfield, 

&c.     Near  Horsham  the  fawn-coloured  sandstone 

is  more  compact,  and  possesses  a  slaty  structure. 

The  thin  slates  are  used  for  roofing,  and  the  thicker 

beds  afford  good  paving-stone ;  their  surfaces  are 

*  Dr.  Fitton. 

A  A  2 


35f>  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

sometimes  deeply  furrowed  by  ripple-marks — an  ap- 
pearance on  which  I  will  offer  a  few  observations. 

38.  RIPPLE-MARKS  ON  SANDSTONE. — The  fur- 
rowed sandstone  and  grit  which  are  used  for  paving 
in  Horsham,  Crawley,  and  other  towns  and  villages 
on  the  Forest-ridge  and  Tilgate  Forest,  must  have 
attracted  the  attention  of  most  persons  who  have 
travelled  from  Brighton  to  London.  The  surface 
of  these  slabs  is  similar  to  what  may  be  observed 
on  the  sand  along  the  sea-shore  at  low  waterr 
when  the  ripple  from  the  receding  waves  has  been 
well  marked ;  the  appearance  has  arisen  from  a 
similar  cause  (see  p.  43).  In  many  instances  the 
stone  is  so  rough  as  to  be  employed  in  stable-yards, 
where  an  uneven  surface  is  required  to  prevent  the 
feet  of  animals  from  slipping  in  passing  over.  It 
sometimes  happens  that  when  a  large  area  of  a 
quarry  is  cleared  from  the  soil  which  covers  it,  a 
most  interesting  appearance  is  presented,  the  whole 
surface  being  rippled  over  like  the  strand  on  the 
sea-shore  ;  and  the  spectator  is  struck  with  the  con- 
viction that  he  is  standing  on  the  sands  of  some 
ancient  delta  or  estuary,  which  are  now  turned  into 
stone.  Sometimes  the  furrows  are  deep,  showing 
that  the  water  was  much  agitated,  and  the  ripple 
strong ;  in  other  instances  the  undulations  are 
gentle,  and  intersected  by  cross  ripples,  proving  a 
change  in  the  direction  of  the  waves.  Some  slabs 
are  covered  by  slightly  elevated,  longitudinal  ridges 
of  sand,  made  up  of  gentle  risings,  disposed  in  a 


§38.  RIPPLE-MARKS  OX  SANDSTONE.  3J7 

crescent-like  manner  ;  these  have  been  produced 
by  the  rills  which  flow  back  into  the  sea,  or  river, 
at  low  water.  In  other  examples,  the  surface  is 
marked  by  angular  ridges  irregularly  crossing  each 
other,  like  the  fissures  in  septaria ;  these  have  obvi- 
ously been  caused  by  deposition  into  crevices  pro- 
duced in  sand  or  mud  by  desiccation.  A  considerable 
portion  of  stone,  the  smooth,  as  well  as  the  furrowed 
surfaces,  is  covered  with  small,  subcylindrical  mark- 
ings, which  are  the  trails  formed  by  some  species 
of  vermes,  or  mollusca ;  but  I  have  searched  in 
vain  for  the  foot-marks  of  the  reptiles  whose  bones 
are  so  abundant  in  the  sandstone.  The  frequent 
occurrence  of  impressions  of  the  feet  of  animals  in 
the  rippled  sandstone  of  other  formations,  renders 
it  probable  that  sooner  or  later  the  tracks  of  the 
iguanodon  and  of  the  hylaeosaurus  will  be  discovered 
on  the  Tilgate  sandstone.  The  deepest  furrows  have 
generally  a  slight  coating  of  bluish  clay,  charged 
with  minute  portions  of  lignite,  and  other  vegetable 
matter ;  an  appearance  which  has  been  occasioned 
by  the  streams  from  the  shore  that  have  flowed  over 
and  coated  the  rippled  sand.  The  furrowed  sand- 
stone presents  an  interesting  example  of  the  perfect 
similarity  of  a  natural  process  in  periods  separated 
from  each  other  by  an  immense  interval  of  time.* 

*  For  a  particular  account  of  the  Wealden  strata  in  the 
south-east  of  England,  see  "  Geology  of  the  South-East  of 
England ;"  and  the  "  Fossils  of  Tilgate  Forest"  For  their 
nature  and  distribution  in  Wilts,  &c.  see  Dr.  Fitton's  Memoir. 


358  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

39.  WEALDEN  OF  THE  ISLE  OF  WIGHT. — De- 
posits partaking  of  the  characters  of  those  I  have 
described,  appear  at  the  back  of  the  Isle  of  Wight, 
and  form  the  lowermost  strata  throughout  the 
southern  half  of  the  island.  Clay,  identical  with 
the  weald  clay,  and  containing  Sussex  marble,  may 
be  seen  at  Sandover  bay,  within  a  few  hundred 
yards  of  the  chalk,  and  extending  into  Red-cliff; 
and  also  at  the  junction,  on  the  east  of  Fresh-water 
bay,  where  the  clay  abounds  in  the  minute  shields 


Shalcomb  Down. 


Compton  Grange. 
Brook-point.    as 


TAB.  67.— SECTION  PKOM  BROOK-POINT  TO  SHALCOMB  DOWN, 
ISLE  OF  WIGHT.* 

1, 1,  Hastings  sand,   a,  Lignite  and  fossil  trunks  of  trees.    2.  Weald  clay. 
3.  Shanklin  sand.    4.  Gait.    5.  Chalk  marl.    6.  Chalk. 

of  cyprides.  At  Brook-point,  the  cliffs,  which  are 
about  thirty  feet  high,  are  formed  of  clay,  with 
inferior  beds  of  soft  sandstone ;  they  contain  lignite, 
and  vegetable  remains  strongly  impregnated  with 
pyrites.  Trunks  of  trees,  of  a  coaly  blackness,  are 
seen  imbedded  in  the  clay  of  the  cliff,  (Tab.  67,  «,) 
and  scattered  on  the  shore.  In  many  of  the  stems 
«  Dr.  Fitton.  Geological  Transactions,  vol.  iv.  PI.  10. 


§  40.  ISLE  OF  PURBECK.  359 

the  ligneous  structure  is  beautifully  preserved,  and 
veined  with  pyrites — other  portions  resemble  jet. 
The  strand  at  low  water  is  seen  to  be  formed  of 
these  fossils ;  and  upon  removing  the  sea-weeds 
which  grow  on  the  shore,  the  petrified  trees  occur 
imbedded  in  masses  of  clay,  which  have  become 
indurated,  and  are  now  in  the  state  of  an  argilla- 
ceous rock :  the  stems  are  from  one  to  two  feet  in 
diameter,  and  eight  or  ten  feet  long.  The  knotty 
bark  and  ligneous  fibre  are  very  distinct.*  Bones 
of  the  iguanodon  and  other  gigantic  reptiles  are 
frequently  found  on  the  shore  at  Sandover-bay  and 
Brook-point,  being  washed  out  of  the  beds  of  the 
wealden,  which  there  form  part  of  the  basin  of  the 
British  Channel. 

40.  ISLE  OF  PURBECK. — The  wealden  beds  are 
next  seen  in  the  Isle  of  Purbeck,  which  lies  on  the 
Dorsetshire  coast,  and  is  of  an  irregular  oval  form, 
being  twelve  miles  in  length,  and  seven  in  breadth. 
On  the  eastern  promontory,  vertical  strata  of  chalk 
occur,  and  beds  of  clay,  sandstone,  and  limestone 
lie  under  the  displaced  chalk ;  towards  the  southern 
extremity  of  the  island,  the  Portland  limestone 
appears.-f- 

Purbeck  has  long  been  celebrated  for  its  quar- 
ries, which  have  been  worked  from  time  imme- 
morial, and  particularly  during  the  middle  ages,  the 

*  From  Mr.  Webster's  interesting  account  of  the  Geology  of 
the  Isle  of  Wight. 

f  Conybeare  and  Phillips. 


360 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


compact  varieties  of  limestone,  which  bear  a  good 
polish,  having,  under  the  name  of  Purbeck  marble, 
been  in  great  request  for  the  religious  edifices  of 
that  period  ;  and  there  is  scarcely  a  cathedral,  or 
ancient  church  in  the  kingdom,  that  is  not  orna- 
mented with  columns,  pavements,  or  sepulchral 
monuments,  constructed  of  this  material.  The 
Purbeck  limestone  abounds  in  organic  remains ; 
and  the  marble  is  a  congeries  of  small  fresh-water 
snail-shells  (paludina),  intermixed  with  the  minute 
crustaceous  coverings  of  a  species  of  cypris.  How 
interesting  is  the  reflection,  that  the  beautiful  cluster- 
columns,  the  richest  ornaments  of  Chichester  cathe- 
dral, are  entirely  composed  of  the  shelly  coverings 
of  snails  and  Crustacea  which  lived  in  the  river  of  a 
country  inhabited  by  extinct  colossal  reptiles  ! 


TAB.  68. — SECTION  IN  ONE  OF  THE  COVES  ON  THE  WEST  OF  THE 
ISLE  OF  PURBECK. 

a,  Chalk;    b,  Chalk-marl;    c,  Firestone;   d,  Gait;   e,  Shanklin  sand; 
/,  Purbeck  beds  ;  g,  Portland  stone. 

The  vertical  position  into  which  so  considerable 
a  portion  of  the  strata  has  been  thrown,  gives  rise 
to  interesting  sections  in  the  coves  on  the  western 


§41.    PETRIFIED  FOREST  OF  THE  ISLE  OF  PORTLAND.   361 

side  of  the  island ;  and,  in  the  precipitous  cliffs  of 
those  basins,  the  chalk,  weald,  Purbeck,  and  Port- 
land strata,  although  vertical,  may  be  seen  in  their 
regular  order  of  succession,  as  is  shown  in  this 
diagram  (Tab.  68).  No  fewer  than  nine  sections 
of  the  beds  between  the  chalk  and  Portland  stone 
(the  upper  division  of  the  oolite,  of  which  I  shall 
speak  in  the  next  lecture)  are  visible  within  the 
space  of  five  miles,  in  the  small  bays  by  which  the 
coast  is  indented.* 

41.  PETRIFIED  FOREST  OF  THE  ISLE  OF  PORT- 
LAND.— The  island,  or  peninsula,  of  Portland  is  a 
bold  headland,  off  Weymouth,  about  four  miles  and 
a  half  in  length,  and  two  in  breadth,  and  is  united 
to  the  main  land  by  the  Chesil  beach.  It  presents  a 
precipitous  escarpment  on  the  north,  and  declining 
towards  the  south,  appears,  on  approaching  it  from 
the  Dorchester  coast,  like  an  inclined  plane,  rising 
abruptly  from  the  ocean.  The  southern  extremity 
is  flanked  by  low  calcareous  cliffs,  which,  from  the 
constant  action  of  the  sea,  are  worn  into  hollows 
and  caverns.  The  base  of  the  island  is  formed  of 
a  blue  clay  (Kimmeridge  clay),  surmounted  by 
thick  beds  of  the  oolitic  limestone,  known  as  the 
Portland  stone,  and  which  is  extensively  quarried 
on  the  northern  brow  of  the  island. 

On  this  oolitic  limestone  are  fresh-water  strata 
(the  lowermost  beds  of  the  wealden  formation), 

*  Dr.  Fitton,  p.  215.  See  Conybeare  and  Phillips'  Geology 
of  England,  p.  159. 


362 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


which  are  characterised  by  phenomena  of  the 
highest  interest.  Mr.  Webster,  in  his  admirable 
geological  memoir  on  the  Isle  of  Wight,  first  di- 
rected attention  to  these  remarkable  deposits.  Upon 


Vegetable  soil. 


Freshwater  lime- 
stone. 


Clay. 


Freshwater  lime- 
stone. 


DIRT-BED,  with 
fossil  trees  and 
Mantellte. 


Freshwater  lime- 
stone. 


DIRT-BED,    with 

Mantellite. 


Portland  oolite; 
a  marine  lime- 
stone. 

Base  of  the 

quarry. 


Total  thickness  about  thirty  feet. 

TAB.  69. — SECTIOX  OF  A  QUARRY  IN  THE  ISLE  OF  PORTLAND. 
(From  Dr.  Fitton's  Memoir  on  the  Strata  below  the  Chalk.) 

the  upper  layer  of  marine  limestone  (Tab.  69,  8), 
which  abounds  in  ammonites,  trigoniae,  and  other 
characteristic  shells  of  the  oolite,  is  a  fresh-water 
limesto  ne,  covered  by  a  layer  of  bituminous  earth, 


§  41.  ISLE  OF  PORTLAND— PETRIFIED  FOREST.  363 

or  vegetable  mould  (4),  which  (as  you  may  perceive 
from  these  specimens,  collected  a  few  years  since,) 
is  of  a  dark  brown  colour,  contains  a  large  propor- 
tion of  earthy  lignite,  and,  like  the  modern  soil  on 
the  surface  of  the  island,  many  water-worn  stones. 
This  layer  is  termed  the  dirt-bed  by  the  workmen  ; 
and  in  and  upon  it  are  trunks  and  branches  of  coni- 
ferous trees,  and  plants  allied  to  the  recent  cycas 
and  zamia.  Many  of  the  trees,  as  well  as  the  plants, 
are  still  erect,  as  if  petrified  while  growing  undis- 
turbed in  their  native  forests,  having  their  roots  in 
the  soil,  and  their  trunks  extending  into  the  upper 
limestone  (see  Tab.  69,  4).  As  the  Portland  stone 
lies  beneath  these  strata,  which  are  not  much  used 
for  economical  purposes,  the  fossil  trees  are  re- 
moved, and  thrown  by  as  rubbish.  On  my  visit  to 
the  island  in  the  summer  of  1832,  the  surface  of  a 
large  area  of  the  dirt-bed  was  cleared,  preparatory 
to  its  removal,  and  a  most  striking  phenomenon  was 
presented  to  my  view.  The  floor  of  the  quarry 
was  literally  strewn  with  fossil  wood  ;  and  I  saw 
before  me  a  petrified,  tropical  forest,  the  trees 
and  the  plants,  like  the  inhabitants  of  the  city  in 
Arabian  story,  being  converted  into  stone,  yet  still 
maintaining  the  places  which  they  occupied  when 
alive  I  Some  of  the  trunks  were  surrounded  by 
a  conical  mound  of  calcareous  matter,  which  had 
evidently  once  been  earth,  and  had  accumulated 
around  the  bases  and  roots  of  the  trees.  The  stems 
were  generally  three  or  four  feet  high,  their  summits 


361  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

being  jagged  and  splintered,  as  if  they  had  been 
torn  and  wrenched  off  by  a  hurricane, — an  appear- 
ance which  many  trees  in  this  neighbourhood,  after 
the  late  storm,  strikingly  resembled.  Some  of  the 
trunks  were  two  feet  in  diameter ;  and  the  united 
fragments  of  one  tree  measured  upwards  of  thirty 
feet  in  length  ;  in  other  specimens,  branches  were 
attached  to  the  stem.  In  the  dirt-bed,  there  were 
many  trunks  lying  prostrate,  and  fragments  of 
branches.  The  fossil  plants  are  called  Cycadeoidea 
by  Dr.  Buckland,  from  their  analogy  to  the  recent 
cycas  and  zamia;*  but  M.  Adolphe  Brongniart 
has  established  a  new  genus  for  their  reception, 
which  he  has  named  Mantellia.  The  plants  oc- 
curred in  the  intervals  between  the  trees ;  and  the 
dirt-bed  was  so  little  consolidated,  that  I  dug  up 
with  a  spade,  as  from  a  parterre,  several  specimens 
that  were  standing  on  the  very  spot  in  which  they 
grew,  having,  like  the  columns  of  Puzzuoli  (Tab. 
14),  preserved  their  erect  position  amidst  all  the 
revolutions  which  had  subsequently  taken  place, 
and  beneath  the  accumulated  spoils  of  number- 
less ages.  The  trees  and  plants  are  completely 
petrified  by  silex,  or  flint  :  you  perceive  that 

*  These  plants  are  so  common  in  green-houses,  that  their 
forms  must  be  well  known.  In  the  conservatories  of  the  Coli- 
seum, in  the  Regent's  Park,  are  fine  examples  of  the  dracaena, 
yucca,  cycas,  and  several  species  of  palms,  allied  to  the  fossil 
plants  of  Tilgate  Forest.  The  magnificent  collection  of  palms 
of  the  Messrs.  Loddige,  of  Hackney,  is  alluded  to  in  my  work 
on  the  Fossils  of  Tilgate  Forest. 


§41. 


ISLE  OF  PORTLAND-PETRIFIED  FOREST. 


3G5 


sparks  are  emitted  upon  striking  a  piece  of  steel 
with  this  fragment  of  what  was  once  a  delicate 
plant;  the  common  forms  of  the  fossil  cycadece, 


TAB.  70.— SILICIFIED  TRUNK  OK  MANTELLIA  NIDIFORMIS. 

(Cycadites  megalophyllus,  Dr.Buckland.*) 

One-fourth  the  natural  size. 

a,  Central  mass  of  cellular  tissue  ;  b,  Circle  of  radiating  woody  plates ; 
c,  Circle  of  cellular  tissue  ;  d,  The  case,  or  false  bark. 

{Mantellia  nidiformis  of  Brongniart,  Tab.  70),  are 

called  crows  nests  by  the  quarry-men.     Our  limits 

will  not  admit  of  a  more  extended  notice  of  these 

*  Dr.  Buckland's  Bridgewater  Essay,  PI.  60. 


366 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


extraordinary  phenomena,  and  I  refer  you  to  the 
memoirs  of  Mr.  Webster,  Dr.  Fitton,  and  Dr.  Buck- 
land.  From  what  has  been  stated,  it  is  evident, 
that  after  the  marine  strata  forming  the  base  of  the 
Isle  of  Portland  were  deposited  at  the  bottom  of  a 
deep  sea,  and  had  become  consolidated,  the  bed  of 
that  ocean  was  elevated  above  the  level  of  the 
waters,  became  dry  land,  and  covered  with  forests. 
How  long  this  new  country  existed,  cannot  be 
ascertained ;  but  that  it  flourished  for  a  considerable 
period  is  certain,  from  the  number  and  magnitude 
of  the  trees  of  the  petrified  forest.  In  the  Isle  of 
Purbeck,  traces  of  the  dirt-bed,  with  the  trunks  of 
trees,  are  seen  beneath  the  fresh-water  limestones 


TAB.  71. — SECTION  OF  THE  CLIFF  EAST  OF  LULWORTH  COVE.* 

1,  Purbeck  calcareous  slate;  2,  Dirt-bed,  with  trunks  of  trees;  3,  Marine 
limestone  of  Portland. 


of  the  weald  ;    a  proof,  that  before  the  deposition 
of  the  Purbeck  marble  could  have  taken  place,  the 

*  Dr.  Buckland. 


}  42.  MODERN  SUBMERGED  FOREST.  367 

petrified  forest  must  have  sunk  to  the  depth  of  many 
hundred  feet.  A  highly  interesting  section  occurs 
on  the  east  of  Lulworth  Cove  (Tab.  71).  It  pre- 
sents a  portion  of  the  dirt-bed,  with  petrified  trunks 
of  coniferous  trees,  standing  in  the  black  mould  in 
which  they  grew  (2),  interposed  between  the  fresh- 
water Purbeck  slate  above  (1),  and  the  marine  Port- 
land limestone  below  (3) ;  the  whole  of  the  strata 
being  in  an  inclined  position.* 

42.  MODERN  SUBMERGED  FOREST. — An  inter- 
esting modern  example  of  the  subsidence  of  a  con- 
siderable tract  of  country  clothed  with  forests,  the 
trees  remaining  erect,  although  submerged  beneath 
a  river  which  still  flows  over  them,  is  described  by 
a  late  American  writer,  and  will  serve  to  illustrate 
the  preceding  remarks.  The  whole  district,  from 
the  Rocky  Mountains  on  the  east  and  the  Pacific 
Ocean  on  the  west,  and  from  Queen  Charlotte's 
Island  on  the  north  to  California  on  the  south, 
presents  one  vast  tract  of  volcanic  formation. 
Basalt,  both  columnar  and  in  amorphous  masses, 
veins  and  dykes,  every  where  occurs,  and  craters  of 
extinct  volcanoes  are  still  visible.  Elevations  and 
dislocations  of  the  strata  have  taken  place  on  an  im- 
mense scale ;  and  successive  beds  of  basalt,  amyg- 
daloidal  trap,  and  breccia,  prove  the  alternation  of 
igneous  action  and  periods  of  repose.  Within  a  few 
miles  of  the  cascades  of  the  river  Columbia,  and 
extending  upwards  of  twenty  miles,  trees  are  seen 
*  Bridgewater  Essay,  vol.  ii.  p.  97. 


368  THE  WONDERS  OF  GEOLOGY.  LECT,  IV' 

standing  in  their  natural  position,  in  a  depth  of 
water  from  twenty  to  thirty  feet.  The  trees  reach 
to  high,  or  fresh-water  mark,  which  is  fifteen  feet 
above  the  lowest  level  of  the  tide  ;  but  they  do  not 
project  beyond  the  freshet  rise,  above  which  their 
tops  are  decayed  and  gone.  In  many  places  the 
trees  are  so  numerous,  that  uwe  had  to  pick  our 
way  with  the  canoe,  as  through  a  forest.  The  water 
of  the  river  was  so  clear,  that  the  position  of  the 
trees  could  be  distinctly  seen  down  to  their  spreading 
roots,  and  they  are  standing  as  in  their  natural  state 
before  the  country  had  become  submerged.  Their 
undisturbed  position  proves  that  the  subsidence  must 
have  taken  place  in  a  tranquil  mariner."  * 

43.  FOSSILS  OF  THE  WEALDEN. — The  organic 
remains  of  the  wealden  consist  of  leaves,  stems  and 
branches  of  plants  of  a  tropical  character ;  bones  of 
enormous  reptiles  of  extinct  genera,  of  crocodiles, 
turtles,  flying  reptiles,  and  birds  ;  of  fishes  of  several 
genera  and  species;  and  fluviatile  shells  and  crus- 
tacea.  The  bones  are,  for  the  most  part,  broken 
and  rolled,  as  if  they  had  been  transported  from  a 
distance.  They  are  strongly  impregnated  with  iron, 
and  are  commonly  of  a  dark-brown  colour ;  their 
cavities  are  frequently  filled  with  white  crystallized 
carbonate  of  lime.  The  bones  in  the  loose  sand 
and  sandstone  are  often  porous  and  friable ;  those 
in  the  Tilgate  grit  are  heavy,  brittle,  and  well 

*  Journal  of  an  Exploring  Tour  beyond  the  Rocky  Moun- 
tains," by  the  Rev.  Samuel  Parker,  A.  M.  New  York.  1838. 


§  44.  FOSSIL  VEGETABLES  OF  THE    WEALDEN.  369 

preserved ;  in  fractured  portions  imbedded  in  the 
limestone,  the  interstices  are  filled  with  calcareous 
spar,  and  the  cancellated  structure  of  the  bones  is 
often  permeated  by  the  same  substance.  The  fossil 
vegetables  occur  bituminized,  and  in  the  state  of 
casts  of  sandstone  ;  the  stems  and  branches  are 
sometimes  silicified  ;  carbonized  leaves  and  twigs 
are  abundant  in  some  of  the  strata.  The  shells  in 
the  clays  have  undergone  but  little  change,  and  in 
many  examples,  the  epidermis  still  remains  ;  in  the 
limestone,  the  substance  of  the  shell  is  converted 
into  spathose  carbonate  of  lime.  With  these  general 
remarks,  I  pass  on  to  the  enumeration  of  the  prin- 
cipal organic  remains. 

44?.  FOSSIL  VEGETABLES — FERNS.  —  From  the 
abundance  of  the  carbonaceous  remains  of  vege- 
tables in  many  of  the  laminated  shales  and  clays 
of  the  wealden,  and  the  occurrence  of  lignite,  or 
brown-coal,  in  masses  and  layers,  which  sometimes 
alternate  with  beds  of  stone  abounding  in  fresh- 
water bivalves,  a  striking  analogy  is  presented  to 
some  of  the  divisions  of  the  coal  measures ;  and 
many  years  since,  this  resemblance  gave  rise  to  a 
search  for  coal  at  Bexhill,  which,  of  course,  proved 
abortive.*  But  notwithstanding  the  prevalence  of 
vegetable  matter  in  the  strata,  specimens  exhibiting 
the  nature  of  the  original  plants,  in  any  tolerable 
degree  of  preservation,  are  rare ;  and,  although  my 

*  Geology  of  the  South-East  of  England,  p.  xviii.  Fossils 
of  the  South  Downs,  p.  35. 

B  B 


370 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


researches  have  been  unremitting,  I  have  obtained 
but  few  fossil  plants  that  will  admit  of  satisfactory 
conclusions  as  to  their  original  structure.  I  shall 
restrict  my  present  remarks  to  a  brief  account  of 
the  principal  varieties,  and  the  circumstances  under 
which  they  occur. 

Entire  layers  of  the  calciferous  grit  of  Tilgate 
Forest  are  so  full  of  minute  portions  of  carbonaceous 


TAB.  72. — SPHENOPTERIS  MANTELLU.    TII.GATE  TOHEST. 
(A  fossil  fern  peculiar  to  the  wealden.) 

matter,*  as  to  acquire  a  dark  mottled  colour ;   and 
upon  examining  the  imbedded  particles,  they  appear 

*  Fossils  of  Tilgate  Forest,  Plate  3,  fig.  6. 


§44. 


FOSSIL  FERNS  OF  THE  WEALDEN. 


371 


to  be  the  detritus  of  plants  ground  to  pieces  by 
agitation  in  sand  and  water.  Specimens  in  my 
possession,  show  that  they  have  been  principally 
derived  from  two  elegant  extinct  species  of  ferns, 
which  are  peculiar  to  the  wealden.  The  one  is  cha- 
racterised by  its  slender  and  minutely  divided  leaflets 
(Sphenopteris  Mantellii — Tab.  72) ;  the  other  by 
the  distribution  of  the  nervures  of  the  leaves  (Lon- 
chopteris  Mantellii — Tab.  73).  This  plant  has  also 
been  found  in  the  valley  of  Bray  by  M.  Graves  of 


TAB  73. — PINNA  OF  LONCHOPTERIS  MANTELLII  :  TILGATE  FOREST. 
(A  fossil  fern,  peculiar  to  the  wealden.) 

Beauvais,  in  the  lower  Boulonnais  in  France,  and 
in  Sweden,  in  strata  supposed  to  be  of  the  same 
epoch  as  the  wealden. 

These  ferns   probably   did    not   exceed   a  few 

feet  in  height ;    I  have  a  stem  of  the  sphenopteris 

which    must   have   belonged    to    a   plant   five    or 

six  feet  high.     Several  other  species  are  associated 

B  B  2 


372 


THE  WONDERS  QF  GEOLOGY. 


LECT.  IV. 


with  these  remains  j  but  the  two  plants  above 
named  constitute  by  far  the  greatest  proportion  of 
the  fossil  vegetables  of  Tilgate  Forest.  My  cabinet 


TAB.  74. — PINNA  OF  A  FERN  IN  FRUCTIFICATION;    IN  SANDSTONE; 
FROM  TILGATE  FOREST. 

Fig.  1.  Natural  size.    2.  Three  leaflets  magnified. 

contains  a  remarkable  specimen,  in  which  the  parts 
of  fructification  are  beautifully  preserved  in  a  sili- 
cified  state  (Tab.  74).  Leaves  of  cycadece,  and 
seed-vessels  of  restiacece,  occur  in  the  ironstone  of 
Heathfield  in  Sussex  ;  they  are  supposed  to  be  of 
the  same  species  as  specimens  from  Bornholm. 
Among  the  plants  from  Heathfield  are  impressions 
which  bear  a  close  resemblance  to  those  of  the  foliage 
of  the  cypress ;  while  others  appear  to  be  refer- 
able to  fuci.  The  stalks  of  a  species  of  mare's-tail 


§  45.  CLATHRARIA  AND  ENDOGENITES.  373 

(Equiselum  Lyellii*)  abound  in  the  blue  limestone 
of  Pounceford. 

4-5.  CLATHRARIA  AND  ENDOGENITES.  —  The 
stems  of  two  plants,  very  distinct  from  each  other, 
are  the  only  vegetables  of  any  considerable  mag- 
nitude that  occur  throughout  the  wealden  of  the 
south-east  of  England.  I  have  not  detected  the 
slightest  trace  of  wood  like  that  of  the  forest  of 
Portland,  nor  observed  any  indications  of  drifted 
and  perforated  masses  similar  to  those  which  are  so 
common  in  the  sands  and  clays  of  the  chalk,  and 
other  formations. 

In  my  former  publication  on  the  fossils  of  Tilgate 
Forest,  I  described  the  plants  which  I  now  place 
before  you.  The  first  species  consists  of  stems, 
with  numerous  tubular  cavities  lined  with  quartz 
crystals,  and  presenting  a  structure  decidedly  ana- 
logous to  the  cacti,  or  euphorbiae ;  they  have  an  ex- 
ternal coating  of  carbonaceous  matter,  and,  on  the 
removal  of  this  coaly  crust,  the  outer  surface  has 
a  remarkably  eroded  appearance.  The  stems  vary 
from  a  few  inches  to  two  feet  in  circumference ;  I 
have  seen  fragments  which,  when  united,  gave  a 
length  of  five  feet.  There  are  no  indications  of 
branches,  but  many  of  the  specimens  taper  at  each 
end,  and  are  of  a  clavated  form,  as  in  some  species 
of  cactus.  Dr.  Fitton  describes  an  assemblage  of 
these  stems,  which  he  observed  before  their  removal, 
imbedded  in  clay,  in  a  cliff  to  the  east  of  the  white- 
*  Geology  of  the  South-East  of  England,  p.  245. 


374  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

rock  at  Hastings  :  they  were  lying  with  their  largest 
diameter  in  a  horizontal  position,  and  consisted  of 
a  silicious  stem  or  nucleus,  coated  by  lignite,  which 
not  only  invested  the  stem,  but  also  extended 
beyond  each  extremity.  The  stems,  when  cut  and 
polished,  exhibit  the  monocotyledonous*  structure; 
Count  Sternberg  considers  them  as  related  to  the 
palms.  This  fossil  vegetable,  from  the  characters 
above  specified,  has  been  named  Endogenites  erosa. 


TAB.  75.— PORTION  OF  THE  STEM  OF  CLATHRARIA  LYJSLLII: 
TILGATE  FOREST. 

(One-fourth  the  natural  size.) 

The  other  plant  (Clathraria^  Lyellii)  bears  an 
analogy  to  the  yucca,  and  dracaena,  or  dragon-blood 

*  Dr.  Fitton  has  given  beautiful  engravings  of  these  fossils 
in  the  Memoir  already  cited,  Plates  XIX.  and  XX. 

f  Clathraria,  from  clathrum,  latticed  or  cross-barred ;  in 
allusion,  to  the  markings  on  the  surface. 


§45. 


FOSSIL  FRUITS  OF  THE  WEALDEN. 


375 


plant.  Stems,  with  the  markings  of  the  bases  of 
the  leaves,  point  out  the  relation  of  this  vegetable 
to  the  arborescent  ferns,*  while  its  internal  structure 
is  essentially  different.  This  interesting  specimen 


TAB.  76. — FRUITS  AND  CONES  OF  THE  WEA.LDEN, 

Fig.  1 .  Seed-vessel  of  Clathraria  Lyellii.    2.  Cone  from  the  Isle  of  Purbeck. 
3.  Cone  from  Kent.    4.  Cone  from  Pippingford.  f 

(Tab.  75,  p.  374)   exhibits  an   internal   axis,  sur- 
rounded by  a  false  bark,  the  surface  of  which  is 

*  The  reader  may  form  an  idea  of  the  height  and  proportions 
of  these  elegant  trees,  by  inspecting  a  specimen  of  tree-fern, 
forty-five  feet  high,  from  Bengal  (alsophila  brunoniana),  on  the 
staircase  of  the  British  Museum. 

t  Figs.  2,  3,  4,  are  reduced  one-half  from  Dr.  Fitton's  Me- 
moir, PI.  XXII. 


376  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

scored  with  the  markings  derived  from  the  attach- 
ment of  the  leaf- stalks.  The  clathraria  has  only 
been  found  in  the  quarries  of  Tilgate  Forest ;  I 
have  fragments  of  stems  indicating  a  large  size. 

46.  SEED-VESSELS. — Not  only  are  the  stems  and 
leaves  of  plants  and  trees  preserved  in  the  wealden 
beds,  but  even  very  delicate  seed-vessels  are  some- 
times found  in  the  grit  and  sandstone.     A  small 
oval  carpolithe  (Tab.  76,  fig.  1)  is  the  most  common. 
M.  Adolphe  Brongniart  considers  it  probable,  that 
this  may  belong  to  the  Clathraria  Lyellii*     The 
seed-vessels  of  coniferous  trees  also  occur.     These 
drawings  (Tab.  76,  figs.  2,  3, 4)  are  from  specimens 
belonging  to  Dr.  Fitton,  who  has  figured  and  de- 
scribed them  in  the  memoir  to  which  I  have  before 
referred  ;     I  particularly  claim  your  attention   to 
fig.  4,  which  is  half  the  size  of  the  original ;    this 
beautiful  cone  was  found  imbedded  in  grit,  in  a 
quarry  on  Ashdown  Forest,  on  the  estate  of  Henry 
Shirley,  Esq.,   and  is  remarkable  for  the  double 
prominences  on  the  scales. 

47.  FOSSIL  SHELLS. — The  shells  of  the  wealden, 
a  series  of  the  principal  species  of  which  I  have 
placed  before  you  (Tab.77),  belong  to  but  few  genera ; 
and  although  whole  tracts  of  country  are  composed  of 
their  remains,  and  many  of  the  limestones  are  mere 
conglomerates  of  shells,   yet   the   species  are  not 
numerous ;  a  character  perfectly  agreeing  with  that 
which  prevails  among  the  existing  genera  of  our 

»  See  Geology  of  the  South-East  of  England,  p.  246. 


§47. 


FOSSIL  SHELLS  OF  THE  WEALDEX. 


377 


rivers.  The  bivalve  shells  chiefly  consist  of  muscles 
(referable  to  a  genus  called  unio  by  conchologists), 
the  casts  of  which  are  abundant  in  some  of  the  sand- 
stones ;  and  several  species  of  cyclas,*  that  occur  in 


<  .8  "^^  9 

TAB.  77. — SHELLS  AND  CRUSTACEA  OP  THE  WEALDEN. 

Fig.  1.  Paludina  Sussexiensis,  from  a  slab  of  Sussex  marble.  2.  Mela- 
nopsis  attenuata.  3.  Neritina  Fittoni,  natural  size,  and  magnified. 
4.  Cyclas.  5.  Psammobia  tellinoides.  6,  Unio  Waited,  with  other 
shells.  7,  9.  Cypris  granulosus,  highly  magnified.  8.  Mytilus  Lyellii. 

myriads  in  the  shales  and  clays,  and  resemble  tertiary 

shells  in  their  state  of  preservation.     The  shales  of 

Pounceford  are  very  like  the  clays  of  Castle  Hill, 

*  A  genus  of  lacustrine,  or  fresh- water  bivalves. 


378  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

Newhaven,  in  respect  to  the  layers  of  shelly  remains 
which  occur  between  the  strata.  The  grey  lime- 
stones are  almost  wholly  composed  of  cyclades,  im- 
bedded in  argillaceo-calcareous  cement,  in  which 
univalves  are  of  rare  occurrence. 

The  calciferous  grit  near  Hastings  is  full  of 
cyclades ;  but  the  shells  are  decomposed,  and  the 
casts  or  impressions  of  the  interior  alone  remain. 
In  the  argillaceous  septaria  of  the  weald  clay,  casts 
of  small  univalves,  also  destitute  of  their  shells, 
abound.  In  Langton-green  quarry,  near  Tunbridge- 
wells,  layers  of  argillaceous  rock  inclose  impressions 
of  numerous  shells ;  and  among  others  a  remarkable 
species  of  unio  (Tab.  77?  fig.  6).  This  spiral  uni- 
valve, melanopsis  attenuate*  (Tab.  66,  and  77,  fig.  2), 
belongs  to  a  freshwater  genus ;  it  occurs  in  the 
shale  at  Pounceford,  in  a  beautiful  state  of  preser- 
vation. This  minute  and  elegant  shell  (Tab.  77, 
fig.  3),  is  dispersed  among  small  snail-shells  in  the 
grit  of  Tilgate  Forest ;  I  have  named  it  neritina 
Fittoni,  in  honour  of  Dr.  Fitton,  whose  able  inves- 
tigations have  so  fully  elucidated  the  geological 
character  and  relations  of  the  deposits  below  the 
chalk. 

48.  SUSSEX,  OR  PETWORTH  MARBLE. — The 
weald-clay  throughout  its  whole  extent  contains 
beds  of  limestone  made  up  of  a  few  species  of 
the  univalve,  called  paludina  (Tab.  77,  fig.  1),  a 
fresh-water  snail,  common  in  rivers  and  lakes.  The 
shells  are  sometimes  decomposed,  and  their  casts 


§  48.  SUSSEX  MARBLE.  379 

alone  remain,  the  interstices  being  filled  up  with 
indurated  marl,  or  calcareous  concretions.     In  the 


TAB.  78.— POLISHED  SLAB  op  SUSSEX  MARBLE. 
(Composed  of  paludince  and  cyprides.) 

coarser  varieties  are  cavities  left  by  the  decompo- 
sition of  the  shells ;  in  the  compact  masses  the 
shells  are  transmuted  into  calcareous  spar,  and  the 
whole  has  been  permeated  by  a  crystalline  calca- 
reous infiltration,  of  various  shades  of  grey,  blue, 
and  ochre,  interspersed  with  pure  white ;  polished 
slabs  display  innumerable  sections  of  the  inclosed 
shells,  and  rival  in  interest  and  beauty  many  foreign 
marbles.  In  these  specimens  you  perceive  the 


380  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

shells  in  relief  on  one  side,  and  sections  of  the 
inclosed  remains  on  the  opposite  polished  surface  ;* 
very  few  bivalves  occur  in  this  limestone,  which, 
from  its  abundance  in  Sussex,  is  commonly  known 
by  the  name  of  Sussex  marble.  The  Petworth  marble, 
and  Bethersden  stone  of  Kent,  are  extensions  of  the 
same  beds.  In  western  Sussex,  a  beautiful  marble 
mottled  with  green,  blue,  and  grey,  occasionally 
occurs ;  it  is  composed  of  large  bivalves  (unio), 
interspersed  with  a  few  univalves  and  fragments  of 
bones  of  reptiles.  The  Purbeck  marble,  already 
described,  only  differs  from  that  of  Sussex  in  the 
size  of  the  shells ;  the  paludinas  in  that  limestone 
being  of  a  very  small  species. 

49.  FOSSIL  CYPRIS, — I  have  stated  that  the  weal- 
den  marbles  are  principally  composed  of  fresh-water 
shells  ;  but  other  animal  remains  enter  into  their 
composition,  and  which,  although  so  minute  as  to 
elude  common  observation,  possess  a  high  degree 
of  interest.  It  has  been  mentioned  that  certain 
crustaceous  animals  (cypris\  abundant  in  fresh- 
water, having  their  bodies  protected  by  shells  or 
cases  which  they  shed  annually,  occur  in  a  fossil 
state  in  the  tertiary  lacustrine  deposits  (page  249)  ; 
and  I  referred  to  the  exhibition  of  the  oxy-hydrogen 
microscope  in  illustration  of  the  forms  of  the  living 
species.  The  shields  of  various  kinds  of  these 
microscopic  creatures  abound  in  the  wealden  clay,-f- 

*  Geology  of  the  South-East  of  England,  p.  184 ;  ibid.  p.  254. 
f  Dr.  Fitton's  Memoir,  PI.  XXI.  figs.  1,  2,  3,  4. 


§  50.  FISHES  OF  THE  WEALDEN.  381 

septaria,  and  limestones,  and  entirely  fill  up  the 
cavities  and  interstices  between  the  shells  in  some 
varieties  of  Sussex  marble.  In  these  specimens  of 
shale  from  near  Lewes,  of  septaria  from  Barcombe, 
and  of  marble  from  Laughton,  by  the  aid  of  a  lens, 
hundreds  of  the  cases  or  shields  of  cyprides  may  be 
detected.  Dr.  Fitton,  who  has  investigated  the 
nature  of  these  minute  relics  with  his  accustomed 
acumen,  has  discriminated  several  species.  These 
enlarged  drawings,  from  his  illustrations,  represent 
a  variety  in  which  the  shells  are  studded  with 
tubercles  (Tab.  77,  figs.  7,  9)*  The  natural  size  of 
these  objects  does  not,  as  you  observe  in  the 
specimens,  exceed  that  of  a  pin's  head,  yet  in  cer- 
tain formations,  entire  layers  of  stone  are  composed 
of  their  consolidated  remains,  and  they  constitute 
a  large  proportion  of  the  mass  of  many  beds  of 
Sussex  marble. 

50.  FISHES. — Detached  bones,  teeth,  and  rays 
of  fishes  of  the  shark  family,  and  of  species  allied 
to  the  large  river-pikes  of  South  America,  are  very 
abundant ;  but  rarely  any  united  portions  of  the 
skeleton,  or  scaly  covering,  are  preserved ;  a  cir- 
cumstance arising  from  the  peculiar  nature  of 
the  wealden  deposits.  Strong,  thick,  enamelled, 
lozenge-shaped  scales,  possessing  a  high  polish,  and 
having  two  processes  of  attachment,  are  very  abun- 
dant in  the  sandstones,  grits,  and  clays  throughout 
the  wealden.  In  St.  Leonard's  and  Tilgate  Forests, 
the  conglomerate  contains  immense  numbers,  asso- 


382  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

elated  with  small  hemispherical  teeth,  called  by 
the  workmen  fishes' -eyes.  These  scales  and  teeth 
belong  to  two  species  of  lepidotus,  or  bony-pike,  of 
which  genus  a  recent  species  inhabits  the  rivers  or 
South  America.  It  is  rarely  that  any  considerable 


TAB.  79.— RESTORED  OUTLINE  op  THE  LEPIDOTUS,  OF  THE  WEALDEX. 
(By  M.  Agassiz.) 

number  of  the  scales  remain  attached  to  each  other 
in  their  natural  position ;  but  I  have  a  few  speci- 
mens in  wliich  large  portions  of  the  scaly  covering 
retain  their  original  character.  These  fishes  must 
have  attained  a  large  size.  In  a  specimen  presented 
to  me  by  Robert  Trotter,  Esq.  F.G.S.  of  Borde  Hill, 
near  Cuckfield,  a  considerable  mass  of  the  united 
scales  is  beautifully  preserved ;  it  is  twelve  inches 
wide,  and  belongs  to  that  part  of  the  body  where 
the  caudal  fin  commences ;  the  fish  must  therefore 
have  been  ten  or  twelve  feet  long,  and  three  feet 
wide.  Tricuspid  teeth  finely  striated,  and  fin-bones 
of  five  or  six  species  of  genera  belonging  to  the 
shark  family,  are  of  frequent  occurrence.  The 


§  31.  REPTILES  OF  TILGATE  FOREST.  3SIJ 

fishes  of  the  wealdeu  are  entirely  distinct  from  those 
of  the  chalk.* 

51.  REPTILES  OF  TILGATE  FOREST. — It  will 
doubtless  excite  your  surprise  to  learn  that  the 
whole  of  the  enormous  bones,  and  teeth,  I  have 
placed  on  the  table,  are  those  of  reptiles,f  and  that 
not  a  vestige  of  any  of  the  mammalia  occurs  in  the 
wealden.  Even  these  teeth,  which  so  strikingly 
resemble  the  incisors  of  the  rhinoceros,  and  these 
bones  of  the  feet  and  toes,  so  similar  in  their  con- 
struction and  magnitude  to  those  of  the  hippopo- 
tamus, all  belong  to  oviparous  quadrupeds  !  Many 
of  the  specimens  before  you  can  be  referred  to 
certain  extinct  forms  of  saurians,  or  lizards ;  but 
others  are  yet  undetermined,  in  consequence  of  my 
want  of  leisure,  and  distance  from  any  extensive 
collection  of  comparative  anatomy.  The  deter- 
mination of  the  fossil  bones  of  the  wealden  is  indeed 
no  easy  task  ;  for  while  in  many  marine  deposits, 
considerable  portions  of  the  skeletons,  or  even  the 
entire  forms,  are  often  discovered ;  in  the  wealden, 
with  the  exception  of  but  three  or  four  examples, 

*  The  following  fishes  of  the  wealden,  in  my  museum,  have 
been  named  by  M.  Agassiz.  Pycnodus  microdon,  Lepidotus 
Fittoni,  L.  Mantellii,  Hybodus  grossiconus,  H.  marginalis, 
H.  polyprion.  A  small  species,  Lepidotus  minor,  occurs  in  the 
Furbeck  limestone. 

f  This  lecture  was  illustrated  by  several  hundred  specimens 
of  bones  and  teeth  of  reptiles  from  the  wealden ;  many  of  such 
enormous  size,  that  the  assemblage  resembled  an  accumulation 
of  the  disjointed  skeletons  of  gigantic  elephants  or  mastodons. 


384  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

every  bone,  tooth,  and  scale,  has  been  found  apart 
from  each  other  ;  and  as  if  to  render  the  task  still 
more  perplexing,  the  relics  of  several  different  spe- 
cies are  scattered,  as  it  were,  at  random  through 
the  rocks.  Every  specimen,  as  I  have  before  re- 
marked, bears  evidence  of  having  been  transported 
from  a  distance ;  it  would  seem  as  if  the  limbs  and 
carcases  of  the  animals  were  floated  down  the  stream, 
and  rolled  backwards  and  forwards  by  the  tides,  and 
the  bones  broken,  before  they  became  imbedded  in 
the  mud  of  the  delta.  To  collect  these  scattered 
fragments,  and  extricate  them  from  the  solid  rock ; 
to  reunite  them  into  a  whole,  and  assign  to  each 
skeleton  of  the  respective  animals,  the  bones  which 
once  belonged  to  it,  yet  not  to  confound  the  dif- 
ferent species  together — such  is  the  labour  which 
the  comparative  anatomist  has  to  perform,  who  un- 
dertakes to  investigate  the  structure  of  the  wealden 
reptiles.  I  reserve  for  the  next  lecture  some  ob- 
servations on  the  economy  and  habits  of  the  reptile 
tribes,  and  will  now  describe  the  fossil  relics  before 
us. 

52.  FOSSIL  TURTLES. — The  bones  and  plates  of 
turtles  are  very  common  in  the  Purbeck  limestone, 
and  in  the  grit,  sandstone,  and  shale  of  Tilgate 
Forest.  They  are  referable  to  two  or  more  fresh- 
water, and  one  marine  species  ;  the  former  appear 
to  be  analogous  to  an  emys,  or  fresh- water  turtle, 
described  by  Cuvier,*  as  occurring  in  the  Jura 
*  Oss.  Foss.  Tom.  V.  p.  232. 


§33.  FOSSIL  CROCODILES.  385 

limestone  at  Soleure.  It  is  a  very  flat  species,  and 
probably  attained  two  feet  in  length.  The  ribs  of 
a  trionyx  (which  is  also  a  fresh-water  turtle),  have 
been  discovered  in  the  shale  of  Pounceford,  and 
grit  of  Tilgate  Forest ;  the  external  surface  of  the 
ribs  or  dorsal  plates  is  shagreened  all  over,  as  is 
usual  in  these  turtles,  which  have  no  shelly  covering, 
but  only  a  thick,  tough  skin,  or  integument;  the 
recent  species  inhabit  the  Nile  and  Euphrates.* 

53.  FOSSIL  CROCODILES. — The  skeletons  of  the 
crocodiles,  alligators,  and  gavials,  those  well-known 
reptiles  of  Egypt,  India,  and  America,  possess 
characters  which  render  their  fossil  bones  easily 
recognisable  by  the  comparative  anatomist.  The 


TAB.  80.— TOOTH  OF  CROCODILE  IMBEDDED  IN  SANDSTONE  ;   FROM 
TILGATE  FOREST. 

peculiar  structure  of  the  teeth,  as  you  may  observe 

in  this  specimen  (Tab.  80),  affords  certain  indications 

*  Geology  of  the  South-East  of  England,  p.  255. 

c  c 


386  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

of  the  original  animal.     The  teeth  of  the  crocodile 
are  very  numerous  ;    they  are  of  a  conical  form 
(Plate  III.  fig.  10),  and  consist  of  a  succession  of 
cones,  like  a  series  of  thimbles,  of  various  sizes, 
fitted  into  each  other ;   they  are  striated  externally, 
and  have  a  prominent  lateral  ridge ;   as  the  outer 
tooth  wears  away,  a  new  one  is  ready  to  supply  its 
place  ;  the  teeth  of  the  old  crocodile  are  therefore  as 
fresh  as  those  of  the  young  animal  but  just  escaped 
from  its  shell.     The  interior  of  the  teeth  is  never 
completely  filled  up ;  hence,  at  whatever  age  a  tooth 
may  be  removed,  there  is  found,  either  in  the  socket, 
or  in  the  cavity  of  the  tooth  itself,  a  new  germ,  in 
a  greater  or  less  state  of  advancement,  ready  to 
occupy  the  place  of  the  old  one,  when  the  latter 
shall  be  removed;   and  this  succession  is  often  re- 
peated.     In  the  fossil   before   us   (Tab.  80),  the 
internal  structure  is  well  displayed,  in  consequence 
of  the  removal  of  a  portion  of  the  external  surface 
of  the  old  tooth.     Detached  bones  of  several  spe- 
cies of  crocodiles  are  scattered  through  the  Tilgate 
strata.     From  the  difference  observable  in  the  form 
of  the  teeth,  they  appear  referable  to  two  kinds — 
the  one  belonging  to  that  division  of  crocodiles, 
with   long   slender  muzzles,    named  gavial ;    the 
other  to  a  species  of  crocodile,  properly  so  called,* 
and    resembling   a   fossil  species   found   at   Caen. 
Among  the  hundreds  of  teeth  and  bones  of  cro- 
codiles collected  in  the  wealden,  no  portions  of  the 
*  Geology  of  the  South-East  of    England,  p.  26. 


§  54.  SWANAGE  CROCODILE.  387 

jaws,  or  any  united  parts  of  the  skeleton,  have  been 
observed ;  but  in  the  Purbeck  beds  a  specimen  has 
recently  been  discovered  that  affords  an  interesting 
illustration  of  the  osteology  of  one  of  the  Tilgate 
species. 


4  3 

TAB.  81.— SECTION  AT  SWANAGE  BAY.« 

1.  Chalk.    2.  Chalk  marl.    3.  Hastings  beds.    4.  Purbeck  limestone. 
5.  Portland  stone. 

54.  THE  SWANAGE  CROCODILE  (Plate  I.) — Swan- 
age,  or  Swanwich,  is  a  little  town  on  the  east  of  the 
Isle  of  Purbeck,  the  inhabitants  of  which  carry  on 
a  brisk  trade  in  the  exportation  of  stone  from  the 
numerous  quarries  in  the  vicinity,  there  being  a 
fine  bay  and  good  anchorage  for  vessels.  The  town 
stands  at  the  mouth  of  the  bay,  about  six  miles 
E.S.E.  of  Corfe  Castle.  The  section  (Tab.  81), 
exposed  by  the  coast,  explains  the  geological  struc- 
ture of  the  country,  and  presents  the  following 
series  of  strata:  —  First,  beds  above  the  chalk; 
secondly,  chalk;  thirdly,  Hastings  beds;  fourthly, 
the  Purbeck  limestone  ;  and  lastly,  the  Portland 
stone,  which  occupies  the  lowermost  place  in  the 
series.  I  need  not,  in  this  place,  dwell  on  the 

*  Dr.  Fitton.     Geological  Transactions,  vol.  iv.  PI.  X.  c. 
cc  2 


388  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

dislocations  of  these  rocks,  and  the  causes  by  which 
they  have  been  disturbed  and  thrown  into  their 
present  position.  In  the  summer  of  1837,  the 
workmen  employed  in  a  quarry,  in  the  immediate 
vicinity  of  Swanage,  had  occasion  to  split  asunder 
a  large  slab  of  the  Purbeck  limestone,  when,  to  their 
great  astonishment,  they  perceived  many  bones  and 
teeth  on  the  surfaces  they  had  just  exposed.  As 
this  was  no  ordinary  occurrence, — for  although  scales 
of  fishes,  shells,  &c.  were  frequently  observed  in 
the  stone,  bones  had  never  before  been  noticed, — 
both  slabs  were  carefully  preserved  by  the  pro- 
prietor of  the  quarry ;  and  fortunately  my  intel- 
ligent friend,  Robert  Trotter,  Esq.  happening  to 
visit  Swanage  a  short  time  afterwards,  heard  of  the 
discovery,  and  with  that  liberality  and  ardour  for 
the  advancement  of  science  for  which  he  is  distin- 
guished, obtained  the  specimens,  and  presented 
them  to  me.  I  have  cleared  away  the  stone,  so  far 
as  the  brittle  state  of  the  bones  will  permit  without 
injury,  and  they  are  now  rendered  two  as  interesting 
groups  of  crocodilian  remains  as  have  been  dis- 
covered in  this  country. 

In  these  specimens  a  considerable  portion  of  the 
left  side  of  the  lower  jaw  (PL  I.  fig.  1),  with  two  teeth 
attached,  is  preserved ;  many  teeth  are  scattered 
over  the  stone,  and  numerous  dermal  (PL  I.  figs.  3, 3), 
or  skin-bones,  which  are  readily  distinguished,  not 
only  by  their  form,  but  also  by  their  deeply  pitted 
surface.  The  pelvis  (PL  I.  figs.  6,  7,  7,  9)  is  nearly 


§55,56,57.        DISCOVERY  OF  THE  IGUANODON.  389 

entire,  and  there  are  many  bones  of  the  spine 
(PI.  I.  figs.  2,  2),  (caudal,  and  dorsal  vertebra,  and 
chevron-bones,  PI.  I.  fig.  5),  ribs  (PL  I.  figs.  4,  4), 
and  some  of  the  long  bones  of  the  extremities. 

55.  THE  PLESIOSAURUS. —  Several  bones,  and 
vertebrae  of  the  neck  and  back  of  the  extraordinary 
extinct  reptile,  called  plesiosaurus,*  whose  remains 
are  found  in  such  prodigious  numbers  in  the  lias, 
occur  in  the  calciferous  sandstone  of  Tilgate  Forest, 
and  prove  that  this  animal  was  an  inhabitant  of  the 
sea  into  which  the  river  of  the  wealden  flowed. 

56.  THE  MEGALOSAURUS.-J- — The  fissile  limestone 
of  Stonesfield,  of  which  I  shall  speak  in  the  next 
lecture,  has  long  been  celebrated  for  the  teeth  and 
bones  of  a  gigantic  reptile,  to  which  Dr.  Buckland 
has  given  the  name  of  megalosaurus.     Vertebrae, 
bones,  and  teeth  of  this  animal  have  been  found  in 
the  Tilgate  grit,  and  in  the  clays  and  sandstones  of 
the  wealden,  associated  with  the  remains  of  turtles, 
crocodiles,   and  the   still  more   colossal   oviparous 
quadruped  the  iguanodon,  which  I  now  proceed  to 
notice. 

57.  THE  IGUANODON  (Plates  II.  and  III). — It  is 
several   years  since  the  discovery  of  a  mutilated 
fragment  of  a  tooth  led  me  to  suspect  the  existence 
of  a  gigantic  herbivorous  animal  in  the  strata  of 
Tilgate  Forest,  which  subsequent  researches  con- 

*  Plesiosaurus,  akin  to  a  lizard  ;  this  reptile  will  be  described 
in  the  fifth  lecture. 

f  Megalosaurus,  great  lizard. 


390  THE  WONDERS  OF  GEOLOGY.  LECT.  IV- 

firmed.*  This  is  the  fragment :  it  is  part  of  the 
crown  of  a  tooth,  resembling  in  its  prismatic  form 
the  incisor  of  one  of  the  herbivorous  mammalia, 
worn  by  use.  The  enamel  is  thick  in  front  and 
thin  behind,  and  by  this  disposition  a  sharp  cutting 
edge  is  maintained  in  every  stage.  Here,  then,  is 
a  character,  which  if  we  bear  in  mind  the  principles 
of  comparative  anatomy  enforced  in  the  second 
lecture,  (page  132,)  will  afford  us  certain  indica- 
tions as  to  the  nature  of  the  animal  to  which  it 
belonged.  The  structure  of  the  tooth,  and  its 
worn  surface,  prove  that  it  is  referable  to  a  species 
that  fed  on  vegetables ;  the  absence  of  a  fang,  and 
the  appearance  of  the  base,  not  broken,  but  indented, 
show  that  the  shank  has  been  absorbed  from  the 
pressure  of  a  new  tooth,  which  has  grown  up  and 
supplanted  the  old  one;  a  process  too  familiar  to 
require  explanation. *|- 

In  the  teeth  before  us  we  trace  every  gradation 
of  this  change,  from  the  perfect  form  (Tab.  82, 
fig.  2,  and  PL  III.  fig.  3), — the  partially  worn  speci- 
mens (Tab.  82,  figs.  4,  5,  and  PL  III.  figs.  6,  7),  to 

*  "  On  the  teeth  of  the  iguanodon,  a  newly-discovered  fossil 
herbivorous  reptile,  from  the  strata  of  Tilgate  Forest." — Philos. 
Trans.  1825. 

f  It  cannot  be  requisite  to  notice  the  vulgar  error  that  the 
first  teeth  in  children  have  no  fangs ;  it  may  however  elucidate 
the  remarks  in  the  text,  if  the  reader  be  reminded  that  the  ab- 
sence of  fangs  in  the  teeth  shed  in  childhood,  results  from  the 
absorption  of  the  fang  of  the  old  teeth,  occasioned  by  the  pres- 
sure of  those  which  are  to  supply  their  place. 


TEETH  OF  THE  IGUANODON. 


391 


the  mere  stump  (figs.  1,  3),  in  which  the  crown  is 
worn  flat,  and  the  absorption  of  the  fang  complete. 


TAB.  82.— TEETH  OP  THE  IGTTANODON,  FROM  TILGATE  FOREST. 

Figs.  1,  3.  Tooth  worn  flat,  and  the  fang  absorbed.  2.  Tooth  of  a  young 
animal.  4.  Outer,  and  5,  inner,  surface  of  a  tooth  of  an  adult.  6.  Late- 
ral view  of  the  serrated  edge  of  fig.  5,  magnified,  a,  The  surface  worn 
by  mastication,  c,  The  indentation  produced  by  pressure  of  the  new 
tooth. 

The  teeth,  when  perfect,  are  of  a  prismatic  form, 
and  remarkable  for  the  prominent  ridges  which  ex- 
tend down  the  front,  and  the  serrated  lateral  margins 
of  the  crown  (Tab.  82,  fig.  6,  the  serrated  edge 


392  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

magnified).  By  a  powerful  microscopic  examination, 
the  ivory  in  the  teeth  of  the  iguanodon  is  found  to 
be  composed  of  close-set  tubes,  radiating  in  a  wavy 
course  from  the  cavity  of  the  pulp  of  the  tooth,  to 
the  superficies,  each  tube  being  also  minutely  un- 
dulated ;  and  this  structure  is  distinctly  seen  on  the 
surface  in  some  examples.* 

But  although  by  this  mode  of  induction  the 
grand  division  of  the  animal  kingdom  to  which 
the  original  belonged  was  ascertained,  a  rigid  com- 
parison of  the  teeth  with  those  of  recent  species 
was  necessary,  to  arrive  at  more  satisfactory  results. 
In  a  fossil  state,  no  teeth  at  all  analogous  had  been 
noticed  ;  and  after  a  fruitless  research  through  the 
collections  of  comparative  anatomy  in  London,  I 
found,  in  the  jaws  of  a  recent  iguana,  f  the  type 
for  which  I  had  so  long  sought  in  vain.  The 
iguanas  are  land  lizards,  natives  of  many  parts  of 
America  and  the  West  Indies,  and  are  rarely  met 
with  north  or  south  of  the  tropics.  They  are  from 
three  to  five  feet  in  length,  and  feed  on  insects  and 
vegetables,  climbing  trees,  and  chipping  off  the 
tender  shoots.  They  nestle  in  the  hollows  of  rocks, 
and  deposit  their  eggs,  which  are  like  those  of 
turtles,  in  the  sands  or  banks  of  rivers.  The  iguana 
is  furnished  with  a  row  of  very  small,  closely-set, 
pointed  teeth,  with  serrated  edges,  which  have  no 

*  Professor  Owen,  "  On  the  structure  of  Teeth,"  &c. 
t  Prepared  by  Mr.  Stutchbury,  the  intelligent  curator  of  the 
Bristol  Institution. 


§  57.  TEETH  OF  THE  IGUANODON.  393 

distinct  alveoli  or  sockets,  but  are  attached  at  the 
base,  and  by  the  outer  surfaces  of  the  fangs,  to 
the  jaw,  the  alveolar  process  forming  an  external 
parapet ;  there  is  no  internal  bony  covering.  The 
new  teeth  do  not,  as  in  the  crocodile,  spring  up  in 
the  centre  of  the  cavities  of  the  old,  and  rise  through 
them,  but  proceed  from  near  the  inner  part  of  their 
base,  and  by  pressure,  occasion  an  absorption  of  a 
portion  of  the  fangs  of  the  old  teeth,  which  they 
ultimately  displace,  by  destroying  their  adhesion  to 
the  dentary  bone.  The  teeth  of  the  iguana  closely 
resemble  the  perfect  fossil  tooth,  Tab.  48,  fig.  2, 
and  Plate  III.  fig.  3,  except  in  size ;  those  of  the 
recent  animal  scarcely  exceeding  in  magnitude  the 
teeth  of  the  common  mouse.  But  in  the  iguana 
the  teeth  never  present  a  worn  surface ;  they  are 
broken  or  chipped  off  by  use,  but  not  ground 
smooth  as  in  the  herbivora.  The  reason  is  obvious; 
none  of  the  existing  reptiles  are  furnished  with 
cheeks  or  moveable  coverings  to  their  jaws,  and 
therefore  cannot  perform  mastication ;  their  food  or 
prey  is  seized  by  the  teeth  and  tongue,  and  swallowed 
whole.  But  apart  from  this  discrepancy,  the  teeth 
and  mode  of  dentition  of  the  fossil  animal  are  so 
perfectly  analogous  to  those  of  the  iguana,  that  I 
have  named  the  original  the  IGUANODON,  signifying 
an  animal  having  teeth  like  the  iguana.  In  the 
course  of  the  last  summer  I  discovered  in  sandstone, 
in  a  quarry  in  Tilgate  Forest,  a  portion  of  the  lower 
jaw  of  the  iguanodon,  that  confirms  the  inferences 


394  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

which  many  years  since  I  ventured  to  deduce  from 
the  structure  of  the  teeth  alone. 

From  the  gigantic  size  of  the  fossil  teeth,  as 
compared  with  the  recent,  I  was  led  to  conclude 
that  many  of  the  colossal  bones,  collected  from 
time  to  time,  in  Tilgate  Forest,  belonged  to  the 
same  kind  of  animal.  By  comparing  the  bones 
with  the  skeleton  of  the  iguana,  (presented  to 
me  by  Baron  Cuvier,)  I  succeeded  in  deter- 
mining many  parts  of  the  skeleton  ;  and  at  length 
was  enabled  to  restore,  as  it  were,  the  form  of 
the  iguanodon,  and  ascertain  its  proportions  ;  the 
correctness  of  my  deductions  was  shortly  to  be 
put  to  the  test,  by  a  discovery  in  a  neighbouring 
county. 

58.  THE  MAIDSTONE  IGUANODON.  (Plate  II.) — 
In  May,  ISS-i,  some  workmen  employed  in  a 
stone-quarry,  in  the  occupation  of  Mr.  W.  H.  Ben- 
sted,  of  Maidstone,  observed  in  a  mass  of  rock 
which  they  had  blasted,  several  portions  of  what 
they  supposed  to  be  petrified  wood ;  they  pre- 
served the  largest  piece  for  the  inspection  of 
Mr.  Bensted,  who  at  once  perceived  that  it  was 
a  portion  of  bone  belonging  to  some  gigantic 
animal.  He  therefore  gave  directions  that  every 
fragment  should  be  collected,  and  after  much  la- 
bour and  research,  succeeded  in  obtaining  those 
pieces,  which  are  now  united,  and  form  a  specimen 
of  the  highest  interest ;  he  also  cleared  away  part 
of  the  surrounding  stone,  so  as  to  expose  many  of 


§58.  THE  MAIDSTONE  IGUANODON.  395 

the  bones,  which  I  have  since  completely  developed 
and  joined  together.* 

The  specimen  consists  of  a  considerable  number 
of  the  bones,  composing  the  inferior  portion  of  the 
skeleton  of  an  iguanodon,  which,  when  living,  must 
have  been  upwards  of  60  feet  in  length.  The  bones 
are  imbedded  in  the  stone  in  a  very  confused  man- 
ner, few  of  them  being  in  their  natural  order  of 
juxta-position,  and  all  more  or  less  flattened  and 
distorted.  The  following  are  well  displayed;  and 
there  are  many  fragments  of  others,  which  are  too 
imperfect  to  admit  of  being  determined. 

Two  thigJi-bones,  each  33  inches  long.f     Plate  II.  figs.  1,  2. 
One  leg-bone  (tibia),  30  inches  long.     Plate  II.  fig.  3. 
Metatarsal  and  phalangeal  bones  of  the  hind  feet ;  these  much 

resemble  the  corresponding  bones  of  the  hippopotamus. 

Plate  II.  figs.  4, 4,  4.  . 
Two  claw-bones  (unguical  phalanges),  which  were  covered  by  the 

nail  or  claw ;   these  correspond  with  the  unguical  bones  of 

the  land  tortoise.     Plate  II.  fig.  5  ;  III.  2. 
Two  finger,  or  metacarpal  bones  of  the  fore-feet,  each  14  inches 

in  length.     Plate  II.  fig.  6. 

A  radius,  or  bone  of  the  fore-arm.     Plate  II.  fig.  7. 
Several  dorsal  and  caudal  vertebra  (bones  of  the  spine  and  tail). 

Plate  II.  figs.  8, 8,  8. 

*  Appendix  L. 

f  The  thigh-bone,  or  femur  of  the  iguanodon  is  very  re- 
markable (Plate  III.  fig.  11) ;  it  has  a  large  trochanter  (a) 
opposite  to  the  head  of  the  bone,  and  a  process  (b)  on  the  inner 
side  for  the  attachment  of  powerful  adductor  muscles ;  the  front 
of  the  lower  extremity  is  deeply  grooved  (d)  anteriorly,  as  in 
the  toad ;  the  shaft  of  the  bone  is  subquadrangular. 


396  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

Fragments  of  several  ribs.     Plate  II.  figs.  9,  9,  9. 

Two  clavicles,  or  collar-bones,  each  28  inches  in  length,  resem- 
bling the  bone  figured  Plate  IV.  figs.  1,  2,  Geology  of  the 
South-East  of  England.  These  bones  are  of  a  very  singular 
form,  and  differ  essentially  from  any  known  clavicle,  yet  it 
seems  impossible  to  assign  them  to  any  other  place  in  the 
skeleton.  Plate  II.  figs.  10,  10. 

Two  large  flat  hatchet-shaped  bones,  which  appear  to  belong  to 
the  pelvis,  and  are  probably  the  ossa  ilia.  PI.  II.  figs.  11, 11. 

A  cJievr  on-lone,  or  one  of  the  inferior  spinous  processes  of  a 
vertebra  of  the  tail.  PI.  II.  fig.  12. 

A  portion  of  a  tooth,  and  the  impression  of  another. — The  pre- 
servation of  these  teeth  is  most  fortunate,  as  the  identity  of 
the  animal  with  the  iguanodon  of  Tilgate  Forest  is  thereby 
completely  established. 

The  geological  position  of  this  specimen  forms  an 
exception  to  what  has  been  previously  remarked  of 
the  fossils  of  the  wealden ;  for  while  the  bones  in 
the  latter  are  found  associated  with  terrestrial  and 
fluviatile  remains  only,  the  Maidstone  specimen  is 
imbedded  in  a  marine  deposit.  This  discrepancy, 
however,  in  no  wise  affects  the  arguments  previously 
advanced,  as  to  the  fluviatile  origin  of  the  strata  of 
the  wealden ;  it  merely  shows  that  part  of  the  delta 
had  subsided,  and  was  covered  by  the  chalk  ocean, 
whilst  the  country  of  the  iguanodon  was  still  in  ex- 
istence, and  the  body  of  an  iguanodon  was  drifted 
out  to  sea,  and  became  imbedded  in  the  sand ;  in 
like  manner,  as  at  the  present  day,  bones  of  land 
quadrupeds  may  not  only  be  engulfed  in  deltas,  but 
also  in  the  deposits  of  the  adjacent  ocean. 

This  specimen  possesses  a  high  interest,  because 
it  proves  that  the  separate  bones  found  in  the  strata 


§  58.  THE  MAIDSTONE  IGUANODON.  39J 

of  Tilgate  Forest,  and  which  I  had  assigned  to  the 
iguanodon,  solely  from  analogy,  have  been  correctly 
appropriated ;  and  we  obtain  also  a  knowledge  of 
many  interesting  facts  relating  to  the  structure  and 
economy  of  the  original.  Thus  as  the  iguana  lives 
chiefly  upon  vegetables,  it  is  furnished  with  long 
slender  feet,  by  which  it  is  enabled  to  climb  trees 
with  facility,  in  search  of  food ;  but  no  tree  could 
have  borne  the  weight  of  the  colossal  iguanodon, — 
its  movements  must  have  been  confined  to  the  land 
and  water,  and  it  is  evident  that  its  enormous  bulk 
must  have  required  limbs  of  great  strength.  Ac- 
cordingly we  find,  that  the  hind  feet,  as  in  the 
hippopotamus,  rhinoceros,  and  other  large  mam- 
malia, were  composed  of  strong,  short,  massy  bones, 
furnished  with  claws,  not  hooked  as  in  the  iguana, 
but  compressed  as  in  the  land  tortoises ;  thus  form- 
ing a  powerful  support  for  the  enormous  leg  and 
thigh.  But  the  bones  of  the  hands,  or  fore  feet, 
are  analogous  to  those  of  the  iguana, — long,  slender, 
flexible,  and  armed  with  curved  claws  (PI.  III. 
fig.  1),  the  exact  counterpart  of  the  nail-bones  of 
the  recent  animal;  thus  furnishing  prehensile  in- 
struments fitted  to  seize  the  palms,  arborescent  ferns, 
and  dragon-blood  plants,  which  probably  consti- 
tuted the  food  of  the  original.  Here  we  have 
another  interesting  example  of  that  admirable  adap- 
tation of  structure  to  the  necessities  and  conditions 
of  every  form  of  existence,  which  is  alike  manifest, 
whether  our  investigations  be  directed  to  the  beings 


398  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

around  us,  or  to  the  organization  of  those  which 
have  long  since  passed  away. 

The  stone  in  which  the  bones  are  imbedded  is  of 
that  hard  variety  of  the  grey,  arenaceous  limestone, 
called  Kentish  rag,  which  is  much  employed  in 
various  parts  of  Kent,  and  in  the  west  of  Sussex, 
for  building,  and  for  repairing  the  roads.  This 
rag  belongs  to  the  Shanklin  sands,  and  abounds  in 
the  marine  shells  which  are  characteristic  of  that 
division  of  the  chalk  formation.  In  the  quarry  in 
which  the  remains  of  the  iguanodon  were  found, 
Mr.  Bensted  has  also  discovered  fossil  wood  per- 
forated by  lithodomi,  or  boring  shells ;  impressions 
of  leaves,  stems  of  trees,  ammonites)  nautili,  &c. ; 
large  conical  striated  teeth,  which  are  referable  to 
some  species  of  sauroid  fishes  ;  scales  and  teeth  of 
several  other  kinds  of  fishes,  and  among  these, 
a  jaw  or  mandible  of  that  singular  genus,  the 
chimera. 

59.  SIZE  OF  THE  IGUANODON. — Gigantic  as  must 
have  been  the  animal  discovered  by  Mr.  Bensted, 
there  are  in  my  collection  many  bones  which  indi- 
cate proportions  yet  more  colossal.  A  thigh  bone 
(PI.  III.  fig.  11),  from  the  west  of  Sussex,  (pre- 
sented to  me  by  J.  Napper,  Esq.)  is  3  feet  8  inches 
long,  and  35  inches  round,  at  the  largest  extremity 
(c) ;  and  the  shaft  of  another  femur  is  24  inches  in 
circumference  !  The  following  is  the  result  of  a 
careful  comparison  of  some  of  the  fossil  bones,  with 
the  corresponding  ones  of  the  iguana,  with  the  view 


5  59.  SIZE  OF  THE  IGUANODON.  399 

of  ascertaining  the  probable  average  size  of  the 
original  animal  (vide  Geol.  of  the  South-East  of 
England,  p.  315);  we  should,  however,  bear  in 
mind,  that  some  individuals  must  have  far  exceeded 
this  estimate,  and,  if  they  bore  the  proportions  of 
the  recent  iguana,  have  been  upwards  of  100  feet 
in  length  ! 

Length  of  the  iguanodon  from  the  snout  to  the  ) 

tip  of  the  tail P°  feet 

„      of  the  head 4$  „ 

„      of  the  body 13  „ 

„      of  the  tail 52£  „ 

Height  from  the  ground  to  the  top  of  the  head        9  „ 

Circumference  of  the  body 14§  „ 

Length  of  the  thigh  and  leg 8  „ 

Circumference  of  the  thigh 7&  ,, 

Length  of  the  hind  foot  from  the  heel  to  thei 
point  of  the  long  toe f 

Of  course  this  calculation  is  offered  but  as  an 
approximation  ;  we  cannot,  however,  for  a  moment 
doubt,  that  an  animal  possessing  a  body  requiring 
thigh  bones  eight  inches  in  diameter  to  support  it, 
must  have  been  of  prodigious  magnitude ;  such 
bones,  if  covered  with  muscles  and  integuments, 
would  form  limbs  upwards  of  seven  feet  in  circum- 
ference I 

The  vertebrae,  or  bones  of  the  spine,  are  generally 
found  detached  and  mutilated ;  but  I  have  one  spe- 
cimen in  which  the  first  six  (caudal)  vertebrae  of 
the  tail  are  admirably  preserved,  and  lie  imbedded 
in  a  block  of  stone  in  their  natural  position  (PI.  III. 


400  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

fig.  8).  The  bodies  of  these  bones  are  slightly  con- 
cave at  both  extremities ;  the  spinous  processes  (a), 
which  are  almost  perfect,  are  15  inches  high.  There 
are  three  chevron  bones  (6,  b),  or  inferior  spinous 
processes,  lying  beneath  the  vertebrae.  The  width, 
or  rather  height,  of  the  tail  to  which  these  bones 
belonged,  must  have  been  at  least  27  inches,  and 
its  entire  length  about  22  feet. 

I  will  notice  one  other  remarkable  feature  in 
the  structure  of  the  iguanodon.  The  iguanas  are 
distinguished  among  the  lizards  by  their  exuberant 
dermal  appendages ;  some  have  serrated  processes 
or  spines  on  the  back,  as  in  this  specimen  from 
Barbadoes,  presented  to  me  by  R.  I.  Murchison, 
Esq.,  late  President  of  the  Geological  Society; 
and  others  on  the  tail ;  while  many  have  warts  and 
horny  protuberances  on  the  head  and  snout.  The 
extraordinary  relic  before  you,  is  the  FOSSIL  HORN 
of  the  iguanodon  (Plate  III.  fig.  5),  from  Tilgate 
Forest.*  It  is  composed  of  bone,  and  bears  marks 
on  its  surface  of  the  integument  with  which  it  was 
invested ;  it  is  four  inches  high ;  the  base,  which  is 
of  an  irregular  elliptical  form,  is  3.2  inches  by  2.1. 
In  this  additional  analogy  between  the  iguanodon 
and  the  iguana,  we  perceive  another  instance  of 
that  law  of  co-relation  of  form  of  which  our  re- 
searches have  afforded  so  many  examples. 

The  fossil  plants  with  which  the  remains  of  the 

*  See  Geology  of  the  South-East  of  England,  p.  312. 
Plate  III.  fig.  5. 


§  60.  THE  HYL/EOSAURUS.  401 

iguanodon  are  associated,  were  furnished  with  tough, 
thick  stems,  like  those  of  the  palms,  tree-ferns, 
yucca,  &c.  These  probably  constituted  the  food  of 
the  original ;  and  the  peculiar  structure  of  its  teeth 
was  evidently  required,  and  admirably  adapted,  for 
the  mastication  of  such  vegetable  productions. 

60.  THE  HYL/EOSAURUS  (  Wealden  lizard,  PI. IV.) 
— In  the  summer  of  1832, 1  discovered,  in  the  lime- 
stone of  Tilgate  Forest,  the  remains  of  a  reptile,  not 
less  extraordinary  than  the  iguanodon,  and  which  I 
have  named  hylceosaurus,  to  denote  its  relation  to 
the  wealden  formation.  A  block  of  calciferous  grit 
had  been  broken  up  by  the  quarrymen,  and  a  great 
part  of  it  thrown  upon  the  road,  as  it  was  not  sup- 
posed to  contain  any  thing  interesting.  Accidentally 
visiting  the  quarry,  I  noticed  indications  of  bones 
in  several  pieces  of  stone  on  the  road-side,  and 
therefore  directed  that  the  remaining  portions  should 
be  collected,  and  sent  to  my  residence.  Having 
cemented  the  fragments  together,  and  chiselled  off 
the  hard  grit  in  which  the  bones  were  wholly  im- 
bedded, and  to  which  they  are  still  attached,  I 
succeeded,  after  much  labour,  in  displaying  a  con- 
siderable portion  of  the  skeleton  of  a  reptile,  which 
blends  the  osteology  of  the  crocodile  with  that  of  the 
lizard.  The  vertebrae  of  the  neck  (PL  IV.  1), 
several  of  the  back  (PL  IV.  2),  many  ribs  (PL  IV.  3), 
and  the  bones  of  the  sternum  (PL  IV.  6),  or  chest, 
remain  ;  there  are  also  dermal,  or  skin-bones,  which, 
in  animals  of  this  family,  support  the  large  scales. 
D  D 


402  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

But  the  most  extraordinary  parts,  are  many  enor- 
mous^ angular,  spinous  bones  (PI.  IV.  4,  5),  which 
lie  in  the  direction  of  the  vertebral  column,  and 
evidently  extended  like  a  serrated  fringe  along  the 
back  of  the  animal.  Many  of  the  existing  lizards, 
particularly  the  cyclura,  have  remarkable  appen- 
dages of  this  kind.  This  figure,  from  Dr.  Harlan's 
valuable  work,  shows  how  largely  these  curious 
processes  are  developed  in  some  species.* 


TAB.  83. — CYCLURA  CARINATA. 
(A  recent  lizard,  allied  to  the  iguana.    Dr.  Jfarlan.) 

The  length  of  the  hylasosaurus  was  probably 
about  twenty-five  feet.  In  the  same  block  of  stone 
were  masses  of  vegetable  remains,  with  seed-vessels, 
and  stems  of  Clathraria  Lyellii.^  I  have  lately 
obtained  many  bones  of  this  extraordinary  creature 
from  a  bed  of  clay  near  Crawley ;  and  also  a  most 
interesting  specimen  of  the  vertebral  column,  com- 

*  Medical  and  Physical  Researches,  by  R.  Harlaii,  M.D., 
F.G.S.,  8vo.  Philadelphia,  1835. 

f  Geology  of  the  South-East  of  England,  p.  316,  PL  V.  is 
an  excellent  lithograph  of  this  specimen,  by  Mr.  Pollard,  of 
West- street,  Brighton. 


§61,  G2.  FOSSIL  BIRDS.  403 

prising  nearly  thirty  vertebrae  of  the  tail  and  back, 
with  many  dermal  and  spinous  bones,  ribs,  &c.  ex- 
hibiting very  peculiar  osteological  characters.  The 
teeth  of  the  hylseosaurus  are  unknown  ;  but  in  the 
quarries  where  the  bones  of  that  reptile  were  dis- 
covered, I  have  found  teeth  of  a  very  peculiar  form 
(PI.  III.  fig.  4),  which  appear  to  have  belonged  to 
a  reptile,  and  are  entirely  distinct  from  those  of  the 
megalosaurus,  iguanodon,  crocodile,  and  plesiosau- 
rus,  whose  remains  occur  in  the  Tilgate  strata. 

61.  FLYING   REPTILES,   or  PTERODACTYLES. — 
The  remains  of  thin  and  slender  bones,  evidently 
belonging  to  animals  capable  of  flight,  were  among 
my    earliest   discoveries    in    the    strata   of  Tilgate 
Forest.     Some  of  these  bones  appear  to  be  refer- 
able to  those  singular  extinct  creatures  called  ptero- 
dactyles,  or  wing-toed  reptiles,  which  had  a  beak 
like  a  bird,  a  long  neck,  and  a  wing  sustained  prin- 
cipally on  an  elongated  toe.     It  is  sufficient  in  this 
place,  merely  to  notice  the  occurrence  of  these  re- 
mains in  the  wealden  ;  the  subject  will  be  resumed 
in  the  succeeding  lecture. 

62.  FOSSIL    BIRDS.  —  In    describing   the   fossil 
remains  of  the  animals  of  the  older  tertiary  epoch, 
it  was  stated  that  several  recent  genera  of  birds 
were  contemporaneous  with  the  palaeotheria  (page 
231);  but  that  no  traces  of  this  class  of  animated 
nature  had  been  found  in  the  chalk,  or  in  strata  of 
an  earlier  date.     The  discovery  of  the  undoubted 
remains   of  birds   in  the   grit  of  Tilgate   Forest, 

DD  2 


404  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

became,  therefore,  a  fact  of  great  interest  and  im- 
portance in  the  physical  history  of  the  globe.  After 
selecting  the  bones  which  appeared  to  belong  to 
pterodactyles,  several  remained  which  bore  so 
striking  a  resemblance  to  those  of  waders,  that  I 
ventured  to  describe  them  as  such  in  my  work  on 
the  Fossils  of  Tilgate  Forest ;  and  this  opinion  was 
corroborated  by  Baron  Cuvier,  to  whom  I  showed 
the  specimens  on  his  last  visit  to  England.  Sub- 
sequently, I  have  obtained  the  inferior  portion  of 
a  leg-bone  (tarso-metatarsal),  in  which  the  oval 
cicatrix,  or  articulation  for  the  hind  toe,  is  distinctly 
visible,  and  proves  unquestionably  that  the  bone 
belonged  to  some  kind  of  wader,  perhaps  a  heron  ; 
the  position  of  the  hind  toe  in  birds,  varying  in 
accordance  with  the  habits  and  economy  of  the 
respective  orders  (page  136).  These  are  the  most 
ancient  remains  of  birds  that  have  hitherto  been 
discovered.* 

63.  THE  COUNTRY  OF  THE  IGUANODON. — By 
this  survey  of  the  strata  and  organic  remains  of  the 
wealden,  we  have  acquired  data  from  which,  by  the 
principles  of  induction,  already  explained  (page  347), 
we  may  obtain  secure  conclusions  as  to  the  nature 
of  the  country  from  whence  those  spoils  were  de- 
rived, of  the  animals  by  which  it  was  inhabited, 
and  of  the  vegetables  that  covered  its  surface. 

*  See  a  Memoir  "  On  the  Bones  of  Birds  discovered  in  the 
Strata  of  Tilgate  Forest,"  by  the  author:  Geological  Trans- 
actions, 1838. 


§  63.         COUNTRY  OF  THE  IGUANODON.         405 

That  country  must  have  been  diversified  by  hill  and 
dale,  by  streams  and  torrents,  the  tributaries  of  its 
mighty  river.  Arborescent  ferns,  palms,  and  yuccas, 
constituted  its  groves  and  forests ;  delicate  ferns  and 
grasses,  the  vegetable  clothing  of  its  soil;  and  in 
its  marshes,  equiseta,  and  plants  of  a  like  nature, 
prevailed.  It  was  peopled  by  enormous  reptiles, 
among  which  the  colossal  iguanodon  and  the  mega- 
losaurus  were  the  chief.  Crocodiles  and  turtles, 
flying  reptiles  and  birds,  frequented  its  fens  and 
rivers,  and  deposited  their  eggs  on  the  banks  and 
shoals;  and  its  waters  teemed  with  lizards,  fishes, 
and  mollusca.  But  there  is  no  evidence  that  Man 
ever  set  his  foot  upon  that  wondrous  soil,  or  that 
any  of  the  animals  which  are  his  contemporaries 
found  there  a  habitation :  on  the  contrary,  not  only 
is  evidence  of  their  existence  altogether  wanting,  but 
from  numberless  observations  made  in  every  part  of 
the  globe,  there  are  conclusive  reasons  to  infer,  that 
man  and  the  existing  races  of  animals  were  not 
created,  till  myriads  of  years  after  the  destruction  of 
the  iguanodon  country — a  country,  which  language 
can  but  feebly  portray,  but  which  the  magic  pencil 
of  a  Martin,  by  the  aid  of  geological  research,  has 
rescued  from  the  oblivion  of  the  past,  and  placed 
before  us  in  all  the  hues  of  nature,  with  its  appalling 
dragon-forms,  its  forests  of  palms  and  tree-ferns,  and 
the  luxuriant  vegetation  of  a  tropical  clime.* 

*  See  the   Frontispiece ;    an   engraving  on   steel,  from  an 
original  painting  by  John  Martin,  Esq.,  K.L. 


406  THE  WONDERS  OF  GEOLOGY.  LECT.  IV. 

64.  SEQUENCE  OF  GEOLOGICAL  CHANGES. — Let 
us  now  review  the  sequence  of  those  stupendous 
changes,  of  which  our  examination  of  the  geolo- 
gical phenomena  of  the  south-east  of  England  has 
afforded  such  incontrovertible  evidence.  From  the 
facts  brought  before  us,  we  learn  that  at  a  period 
incalculably  remote,  there  existed  in  the  northern 
hemisphere  an  extensive  island  or  continent,  pos- 
sessing a  climate  of  such  a  temperature,  that  its 
surface  was  clothed  with  coniferous  trees,  arbores- 
cent ferns,  and  plants  allied  to  the  cycas  and  zamia; 
and  that  the  ocean  which  washed  its  shores  was 
inhabited  by  turtles  and  reptiles  of  extinct  genera. 
This  island  and  its  forests  suffered  a  partial  subsi- 
dence, which  was  effected  in  such  manner  that  many 
of  the  trees,  although  torn  and  rent,  still  retained 
their  erect  position  ;  and  the  zamise,  and  a  consi- 
derable layer  of  the  vegetable  mould  in  which  they 
grew,  remained  undisturbed.  In  this  state  an  inun- 
dation of  fresh-water  covered  the  once  flourishing 
forest,  and  deposited  upon  the  soil  and  around  the 
trees  a  calcareous  mud,  which  gradually  consoli- 
dated into  fine  limestone ;  water,  holding  flint  in 
solution,  percolated  through  the  mass,  and  silicified 
the  now  submerged  trees  and  plants.  A  further 
depression  took  place  —  a  body  of  fresh  water, 
brought  down  by  land -floods  and  rivers,  over- 
whelmed the  petrified  forest,  and  heaped  upon  it 
accumulations  of  debris,  which  their  parent  streams 
had  washed  away  from  the  rocks  over  which  they 


§  64.  GEOLOGICAL  CHANGES.  407 

had  flowed.  The  country  traversed  by  the  rivers, 
like  that  of  the  submerged  forest,  enjoyed  a  tropical 
climate ;  it  was  clothed  with  palms,  arborescent 
ferns,  and  plants  allied  to  the  yucca  and  the  dra- 
caena,  and  tenanted  by  enormous  reptiles,  croco- 
diles, and  land  and  fresh-water  turtles ;  and  in  its 
waters  were  various  kinds  of  fishes,  mollusca,  and 
aquatic  plants.  The  bones  and  teeth  of  the  reptiles 
—the  remains  of  the  turtles— the  teeth  and  scales 
of  fishes — the  shells  of  the  snails  and  muscles  — 
the  stems,  leaves,  and  even  seed-vessels,  of  the 
trees,  were  carried  down  by  the  stream,  and  de- 
posited in  the  mud  of  the  delta,  beneath  which 
the  petrified  forest  was  now  buried.  This  state 
continued  for  a  long  period :  another  change  took 
place  ;  the  country  and  its  inhabitants  were  swept 
away,  and  the  delta,  and  the  strata  on  which  it 
reposed,  were  submerged  to  a  great  depth,  and 
formed  part  of  the  bottom  of  a  profound  ocean, 
whose  waters  teemed  with  myriads  of  zoophytes, 
shells,  and  fishes,  of  species  that  are  now  no  more. 
Thermal  waters,  holding  calcareous  and  silicious 
matter  in  solution,  were  poured  into  its  basin,  and, 
in  its  tranquil  depths,  layers  of  flint  and  chalk  were 
deposited.  And  so  rapidly  were  these  changes 
effected,  that  fishes,  while  in  the  act  of  swimming, 
were  arrested  in  their  progress,  and  became  suddenly 
enveloped  in  a  bed  of  rock.  This  epoch  was  of 
considerable  duration  :  at  length  elevatory  move- 
ments began  to  take  place,  the  bottom  of  the  deep 


408  THE  WONDERS  OF  GEOLOGY.  LECT.  iv. 

was  slowly  up-heaved,  and  as  the  elevation  con- 
tinued, the  depositions  which  had  formed  in  the 
basin  of  the  ocean,  and  had  become  consolidated, 
were  broken  up,  and  as  they  approached  the  surface 
were  acted  upon  by  the  waves.  The  chalk  strata 
now  began  to  suffer  degradation  and  destruction, 
and  the  delta  of  the  country  of  the  iguanodon 
emerged  above  the  waters ;  and  finally,  even  the 
ancient  petrified  forest  was  brought  to  view,  and 
became  dry  land.  At  length  some  masses  rose  to 
an  elevation  of  a  few  hundred  feet  above  the  level 
of  the  sea,  and  formed  a  group  of  islands ;  but,  in 
the  depressions  of  the  strata  beneath  the  waters, 
deposits  went  on,  from  the  waste  of  the  cliffs  on 
the  sea-shores.  Large  mammalia  now  inhabited 
such  portions  of  the  former  ocean-bed  as  were 
clothed  with  vegetation,  and  as  they  died  their 
skeletons  were  enveloped  in  the  accumulations  of 
mud  and  gravel  which  were  forming  in  the  bays 
and  estuaries.  This  era  also  passed  away — the 
elevation  continued — other  portions  of  the  bed  of 
the  chalk-ocean  became  dry  land — and  at  length 
also  those  newer  strata,  iri  which  the  remains  of 
the  mammoth  and  the  elk,  the  last  tenants  of  the 
country,  were  entombed.  The  oak,  elm,  ash,  and 
other  trees  of  modern  Europe,  sprang  up  where 
the  palms  and  tree-ferns  once  flourished ;  the  deer, 
boar,  and  horse,  ranged  where  the  mighty  reptiles 
once  ruled  sole  monarchs  of  the  country;  and 
lastly,  man  appeared,  and  took  possession  of  the 


§  65.         RETROSPECT  OF  GEOLOGICAL  MUTATIONS.         400 

soil.  At  the  present  time,  a  city*  stands  on  the 
deposits  which  contain  the  remains  of  the  elephant 
and  the  elk ;  the  huntsman  courses,  and  the  shep- 
herd tends  his  flocks,  on  the  elevated  and  rounded 
masses  of  the  bottom  of  the  ancient  chalk-ocean  ;-|- 
the  farmer  reaps  his  harvests  upon  the  cultivated 
soil  of  the  delta  of  the  iguanodon  ;  J  and  the  archi- 
tect seeks,  beneath  the  petrified  forest,  for  the 
materials  with  which  to  construct  his  edifices. 

65.  RETROSPECT  OF  GEOLOGICAL  MUTATIONS. 
— Such  is  a  plain  enunciation  of  the  results  of  our 
investigations ;  but  I  will  embody  these  inductions 
in  a  more  impressive  form,  by  employing  the  meta- 
phor of  an  Arabian  writer,  and  imagining  some 
higher  intelligence  from  another  sphere,  to  describe 
the  physical  mutations  of  which  he  may  be  supposed 
to  have  taken  cognizance,  from  the  period  when  the 
forests  of  Portland  were  flourishing,  to  the  present 
time.  Countless  ages  ere  man  was  created,  he  might 
say,  I  visited  these  regions  of  the  earth,  and  beheld 
a  beautiful  country  of  vast  extent,  diversified  by 
hill  and  dale,  with  its  rivulets,  streams,  and  mighty 
rivers,  flowing  through  fertile  plains.  Groves  of 
palms  and  ferns,  and  forests  of  coniferous  trees, 
clothed  its  surface ;  and  I  saw  monsters  of  the 
reptile  tribe,  so  huge  that  nothing  among  the  ex- 
isting races  can  compare  with  them,  basking  on  the 
banks  of  its  rivers  and  roaming  through  its  forests ; 

*  Brighton.  f  The  South  Downs. 

The  wealds  of  Kent  and  Sussex. 


410  THE  WONDFUS  OF  GEOLOGY.  LECT.  IV. 

while,  in  its  fens  and  marshes,  were  sporting  thou- 
sands of  crocodiles  and  turtles.  Winged  reptiles  of 
strange  forms  shared  with  birds  the  dominion  of  the 
air,  and  the  waters  teemed  with  fishes,  shells,  and 
Crustacea.  And  after  the  lapse  of  many  ages  I 
again  visited  the  earth  ;  and  the  country,  with  its 
innumerable  dragon-forms,  and  its  tropical  forests, 
all  had  disappeared,  and  an  ocean  had  usurped  their 
place.  And  its  waters  teemed  with  nautili,  ammo- 
nites, and  other  cephalopoda,  of  races  now  extinct; 
and  innumerable  fishes  and  marine  reptiles.  And 
thousands  of  centuries  rolled  by,  and  I  returned, 
and,  lo  !  the  ocean  was  gone,  and  dry  land  had 
again  appeared,  and  it  was  covered  with  groves  and 
forests;  but  these  were  wholly  different  in  character 
from  those  of  the  vanished  country  of  the  iguanodon. 
And  I  beheld,  quietly  browsing,  herds  of  deer  of 
enormous  size,  and  groups  of  elephants,  mastodons, 
and  other  herbivorous  animals  of  colossal  magni- 
tude. And  I  saw  in  its  rivers  and  marshes  the 
hippopotamus,  tapir,  and  rhinoceros;  and  I  heard 
the  roar  of  the  lion  and  the  tiger,  and  the  yell  of 
the  hyena  and  the  bear.  And  another  epoch  passed 
away,  and  I  came  again  to  the  scene  of  my  former 
contemplations  ;  and  all  the  mighty  forms  which  I 
had  left  had  disappeared,  the  face  of  the  country  no 
longer  presented  the  same  aspect ;  it  was  broken 
into  islands,  and  the  bottom  of  the  sea  had  become 
dry  land,  and  what  before  was  dry  land  had  sunk 
beneath  the  waves.  Herds  of  deer  were  still  to 


§66.         RETROSPECT  OF  GEOLOGICAL  MUTATIONS.          41 1 

be  seen  on  the  plains,  with  swine,  and  horses,  and 
oxen  ;  and  wolves  in  the  woods  and  forests.  And 
I  beheld  human  beings,  clad  in  the  skins  of  animals, 
and  armed  with  clubs  and  spears ;  and  they  had 
formed  themselves  habitations  in  caves,  constructed 
huts  for  shelter,  inclosed  pastures  for  cattle,  and 
were  endeavouring  to  cultivate  the  soil.  And  a 
thousand  years  elapsed,  and  I  revisited  the  country, 
and  a  village  had  been  built  upon  the  sea-shore,  and 
its  inhabitants  supported  themselves  by  fishing ; 
and  they  had  erected  a  temple  on  the  neighbouring 
hill,  and  dedicated  it  to  their  patron  saint.  And 
the  adjacent  country  was  studded  with  towns  and 
villages ;  and  the  downs  were  covered  with  flocks, 
and  the  valleys  with  herds,  and  the  corn-fields 
and  pastures  were  in  a  high  state  of  cultivation, 
denoting  an  industrious  and  peaceful  community. 
And  lastly,  after  an  interval  of  many  centuries,  1 
arrived  once  more,  and  the  village  was  swept  away, 
and  its  site  covered  by  the  waves ;  but  in  the 
valley  and  on  the  hills  above  the  cliffs  a  beautiful 
city  appeared ;  with  its  palaces,  its  temples,  and  its 
thousand  edifices,  and  its  streets  teeming  with  a 
busy  population  in  the  highest  state  of  civilization ; 
the  resort  of  the  nobles  of  the  land,  the  residence 
of  the  monarch  of  a  mighty  empire.  And  I 
perceived  many  of  its  intelligent  inhabitants  ga- 
thering together  the  vestiges  of  the  beings  which 
had  lived  and  died,  and  whose  very  forms  were 
now  obliterated  from  the  face  of  the  earth,  and 


412 


THE  WONDERS  OF  GEOLOGY. 


LECT.  IV. 


endeavouring,  by  these  natural  memorials,  to  trace 
the  succession  of  those  events  of  which  I  had  been 
the  witness,  and  which  had  preceded  the  history  of 
their  race.* 

*  The  concluding  portion  of  these  remarks  refers  to  the 
changes  that  have  taken  place  on  the  Sussex  coast,  during  the 
historical  era.  Before  the  Conquest,  the  greater  part  of  the  little 
fishing  town  of  Brighthelmston  (BrigJithelms-toivn],  or  Brighton, 
was  situated  below  the  cliffs,  on  a  terrace  of  beach  and  sand,  now 
covered  by  the  waves.  The  Church,  dedicated  to  St  Nicholas, 
the  patron  saint  of  fishermen,  was  placed  on  an  eminence,  that 
it  might  serve  as  a  land-mark.  The  inroads  of  the  sea  led  to 
the  erection  of  buildings  on  the  high  ground,  and  its  progressive 
encroachment  gradually  diminished  the  area  of  the  ancient  town, 
till  at  length  a  sudden  inundation,  but  little  more  than  a  century 
ago,  swept  away  the  houses,  fortifications,  and  inclosures,  that 
remained.0  The  sea  has,  therefore,  only  resumed  its  former 
position  at  the  base  of  the  cliffs  ;  the  site  of  the  old  town  having 
been  an  ancient  bed  of  shingle,  abandoned  for  ages  by  the  ocean, 
perhaps  contemporaneously  with  the  retreat  of  its  waters  from 
the  valley  of  the  Ouse.  Should  the  advancement  of  the  sea  be 
still  progressive,  Lewes  Levels  may  again  become  an  estuary, 
and  the  town  of  the  Cliff,  and  the  hamlet  of  Landport,  regain 
the  characters  from  which  their  names  were  derived.  See  page  45. 


«  Illustrations  of  the  Geology  of  Sussex,  page  292.  Geology 
of  the  South-East  of  England,  page  23.  Dallaway's  Western 
Sussex,  Vol.  I.  page  55. 


APPENDIX. 


A.  Page  21. — THE  SURFACE  OF  THE  MOON. — The  moon 
is  the  only  planetary  body  placed  sufficiently  near  us,  to 
have  the  inequalities  of  its  surface  rendered  distinctly  visible 
with  the  telescope.  Attendant  on  the  earth,  and  having 
nearly  the  same  density,  we  may  reasonably  infer  that  the 
mineral  substances  of  which  it  is  composed  do  not  differ 
essentially  from  those  on  the  surface  of  our  own  planet. 
Astronomers  now  generally  admit  that  the  moon  is  sur- 
rounded by  a  very  clear  atmosphere,  but  which  is  so  low 
that  it  scarcely  occasions  a  sensible  refraction  of  the  rays 
of  light  when  it  passes  over  the  fixed  stars.  Many  of  the 
dark  parts  of  the  moon,  particularly  the  part  called  mare 
crisium,  appear  to  be  covered  with  a  fluid,  which  may  pro- 
bably be  more  transparent  and  less  dense  than  water,  as 
the  form  of  the  rocks  and  craters  are  seen  beneath  it,  but 
not  so  distinctly  as  in  the  lighter  parts  of  the  moon's  sur- 
face. To  examine  the  moon  with  a  reference  to  its  exter- 
nal structure,  the  defining  power  of  the  telescope  should  be 
of  the  first  quality,  sufficient  to  show  the  projections  of  the 
outer  illuminated  limb  as  distinctly  as  they  appear  when 
the  moon  is  passing  over  the  disk  of  the  sun  during  a  solar 
eclipse.  With  such  a  telescope,  and  a  sufficient  degree  of 
light  and  of  magnifying  power,  almost  every  part  of  the 
moon's  surface  appears  to  be  volcanic,  containing  craters  of 
enormous  magnitude  and  vast  depth :  the  shelving  rocks, 
and  the  different  internal  ridges  within  them,  mark  the 
stations  at  which  the  lava  has  stood  and  formed  a  floor 
during  different  eruptions ;  while  the  cones  in  some  of  the 
craters  resemble  those  formed  within  modern  volcanoes. 
The  largest  mountain  on  the  southern  limb  of  the  moon, 
like  the  largest  volcanic  cone  on  the  earth,  Chimborazo, 


414  APPENDIX. 

has  no  deep  crater  on  its  summit.  There  are  indeed  the 
outlines  of  the  crater,  but  it  is  nearly  filled  up  ;  while  from 
the  foot  of  this  lunar  mountain  diverging  streams  of  lava 
seem  to  flow  in  different  directions,  to  the  distance  of  six 
hundred  miles.  The  longest  known  current  of  modern 
lava  on  the  earth  is  in  Iceland ;  it  extends  sixty  miles  ;  but 
the  volcanoes  in  that  island  bear  no  proportion  to  those  of 
the  moon  in  magnitude. — Mr.  Bakewell. 


B.  Page  60. — THE  LAKE  OF  THE  SOLFATARA. — Its  tem- 
perature was,  in  the  winter,  in  the  warmest  parts,  above 
80  deg.  of  Fahrenheit,  and  it  appears  to  be  pretty  constant; 
for  I  have  found  it  to  differ  a  few  degrees  only,  in  January, 
March,  May,  and  the  beginning  of  June  ;  being  nearly 
twenty  degrees  above  the  mean  temperature  of  the  atmo- 
sphere, it  must  therefore  be  supplied  with  heat  from  a  sub- 
terraneous source.  Kircher  lias  detailed  in  his  Mundm 
Subterraneus  various  wonders  respecting  this  lake,  most  of 
which  are  unfounded,  such  as  that  it  is  unfathomable,  that 
it  has  at  the  bottom  the  heat  of  boiling  water,  and  that 
floating  islands  rise  from  the  gulf.  It  must  certainly  be  very 
difficult,  or  even  impossible  to  fathom  a  source  which  rises 
with  so  much  violence  from  a  subterraneous  excavation ; 
and  at  a  time  when  chemistry  had  made  small  progress,  it 
was  easy  to  mistake  the  disengagement  of  carbonic  acid 
for  an  actual  ebullition.  The  floating  islands  are  real,  but 
neither  the  Jesuit  nor  any  of  the  writers  who  have  since 
described  this  lake,  have  had  a  correct  idea  of  their  origin, 
which  is  exceedingly  curious.  The  high  temperature  of 
this  water,  and  the  quantity  of  carbonic  acid  that  it  con- 
tains, render  it  peculiarly  fitted  to  afford  a  pabulum  or 
nourishment  to  vegetable  life ;  the  banks  of  travertine 
are  every  where  covered  with  reeds,  lichens,  confervas,  and 
various  kinds  of  aquatic  vegetables.  At  the  same  time 
that  the  process  of  vegetable  life  is  going  on,  the  crystalli- 
zation of  the  calcareous  matter,  which  is  every  where 
deposited  in  consequence  of  the  escape  of  carbonic  acid, 
likewise  proceeds,  and  gives  a  constant  milkiness  to  what 
from  its  tint  would  otherwise  be  a  blue  fluid.  So  rapid  is 
the  vegetation,  owing  to  the  decomposition  of  the  carbonic 


APPENDIX.  415 

acid,  that  even  in  winter  masses  of  confervae  and  lichens, 
mixed  with  deposited  travertine,  are  constantly  detached 
hy  the  currents  of  water  from  the  hank,  and  float  down  the 
stream,  which  being  a  considerable  river,  is  never  without 
many  of  these  small  islands  on  its  surface.  They  are  some- 
times only  a  few  inches  in  size,  and  composed  merely  of 
dark  green  confervae,  or  purple  or  yellow  lichens  ;  but, 
occasionally,  are  even  several  feet  in  diameter,  and  con- 
tain seeds  and  various  species  of  common  water-plants, 
which  are  usually  more  or  less  incrusted  with  marble. 
There  is,  I  believe,  no  place  in  the  world  where  there  is  a 
more  striking  example  of  the  opposition  or  contrast  of  the 
laws  of  animate  and  inanimate  nature,  of  the  forces  of 
inorganic  chemical  affinity,  and  those  of  the  powers  of  life. 
Vegetables,  in  such  a  temperature,  and  every  where  sur- 
rounded by  food,  are  produced  with  a  wonderful  rapidity ; 
but  the  crystallizations  are  formed  with  equal  quickness, 
and  are  no  sooner  produced  than  they  are  destroyed  toge- 
ther. Notwithstanding  the  sulphureous  exhalations  from 
the  lake,  the  quantity  of  vegetable  matter  generated  there, 
and  its  heat,  make  it  the  resort  of  an  infinite  variety  of 
insect  tribes ;  and,  even  in  the  coldest  days  in  winter, 
numbers  of  flies  may  be  observed  on  the  vegetables  sur- 
rounding its  banks,  or  on  its  floating  islands.  Their  larvae 
may  also  be  seen  there,  sometimes  incrusted  and  entirely 
destroyed  by  calcareous  matter,  as  well  as  the  insects  them- 
selves, and  various  species  of  shell-fish  that  are  found 
amongst  the  vegetables  which  grow  and  are  destroyed  in 
the  travertine  on  its  banks.  Snipes,  ducks,  and  other 
water-birds,  often  visit  these  lakes,  probably  attracted  by 
the  temperature  and  the  quantity  of  food  in  which  they 
abound ;  but  they  usually  confine  themselves  to  the  banks, 
as  the  carbonic  acid  disengaged  from  the  surface  would  be 
fatal  to  them,  if  they  ventured  to  swim  upon  it  when  tran- 
quil. In  May  18 — ,  I  fixed  a  stick  on  a  mass  of  travertine 
covered  by  the  water,  and  examined  it  in  the  beginning  of 
the  April"  following,  for  the  purpose  of  determining  the 
nature  of  the  depositions.  The  water  was  lower  at  this 
time ;  yet  I  had  some  difficulty,  by  means  of  a  sharp- 
pointed  hammer,  in  breaking  the  mass  which  adhered  to 
the  bottom  of  the  stick ;  it  was  several  inches  in  thickness. 
The  upper  part  was  a  mixture  of  light  tufa  and  leaves  of 


416  APPENDIX. 

confervas  ;  below  this  was  a  darker  and  more  compact 
travertine,  containing  black  and  decomposed  masses  of 
confervse ;  in  the  inferior  part,  the  travertine  was  more 
solid,  and  of  a  grey  colour,  but  with  cavities  which  I  have 
no  doubt  were  produced  by  the  decomposition  of  vegetable 
matter.  I  have  passed  many  hours,  I  may  say  days,  in 
studying  the  phenomena  of  this  wonderful  lake  ;  it  has 
brought  trains  of  thought  into  my  mind  connected  with 
the  early  changes  of  our  globe  ;  and  I  have  sometimes 
reasoned  from  the  forms  of  plants  and  animals  preserved 
in  marble  in  this  thermal  source,  to  the  grander  depositions 
in  the  secondary  rocks,  where  the  zoophytes  or  coral  insects 
have  worked  upon  a  grand  scale,  and  where  palms  and 
vegetables,  now  unknown,  are  preserved  with  the  remains 
of  crocodiles,  turtles,  and  gigantic  extinct  saurian  animals, 
which  appear  to  have  belonged  to  a  period  when  the  whole 
globe  possessed  a  much  higher  temperature.  I  have  like- 
wise often  been  led,  from  the  remarkable  phenomena 
surrounding  me  in  that  spot,  to  compare  the  works  of  man 
with  those  of  nature.  The  baths,  erected  there  nearly 
twenty  centuries  ago,  present  only  heaps  of  ruins,  and 
even  the  bricks  of  which  they  were  built,  though  hardened 
by  fire,  are  crumbled  into  dust ;  whilst  the  masses  of  tra- 
vertine around,  though  formed  by  a  variable  source  from 
the  most  perishable  materials,  have  hardened  by  time,  and 
the  most  perfect  remains  of  the  greatest  ruins  in  the  eternal 
city,  such  as  the  triumphal  arches  and  the  Colosseum,  owe 
their  duration  to  this  source. 

How  marvellous  are  those  laws  by  which  the  humblest 
types  of  organic  existence  are  preserved,  though  born 
amidst  the  sources  of  their  destruction,  and  by  which  a 
species  of  immortality  is  given  to  generations  floating,  as  it 
were,  like  evanescent  bubbles  on  a  stream  raised  from  the 
deepest  caverns  of  the  earth,  and  instantly  losing  what 
may  be  called  its  spirit  in  the  atmosphere. — Sir  Humphrey 
Davys  Last  Days  of  a  Philosopher. 


C.  Page  62.  —  CAVERNS.  —  One  of  the  most  common 
appearances  in  limestone  caverns,  is  the  formation  of 
what  are  called  stalactites,  from  a  Greek  word  signifying 


APPENDIX.  417 

distillation,  or  dropping.  To  explain  these,  a  brief  de- 
scription of  the  mode  of  their  production  will  be  necessary. 
Whenever  water  filters  through  a  limestone  rock,  it  dissolves 
a  portion  of  it ;  and  on  reaching  any  opening,  such  as  a 
cavern,  either  at  its  sides  or  roof,  it  forms  a  drop,  the 
moisture  of  which  is  soon  evaporated  by  the  air,  leaving  a 
small  circular  plate  of  calcareous  matter ;  another  drop 
succeeds  in  the  same  place,  and  adds,  from  the  same  cause, 
a  fresh  coat  of  incrustation.  In  time,  these  successive 
additions  produce  a  long,  irregular,  conical  projection  from 
the  roof,  which  is  continually  being  increased  by  the  fresh 
accession  of  water  loaded  with  calcareous  or  chalky  matter, 
which  it  deposits  on  ;  the  outside  of  the  stalactite  already 
formed,  and  trickling  down,  adds  to  its  length  by  subsiding 
to  the  point,  and  being  dried  up  as  before ;  precisely  in 
the  same  manner  as  during  frosty  weather,  icicles,  which 
are  stalactites  of  ice,  or  frozen  water,  are  formed  on  the 
edges  of  the  eaves  of  a  roof.  When  the  supply  of  water 
holding  lime  in  solution  is  too  rapid  to  allow  of  its  evapo- 
ration at  the  bottom  of  the  stalactite,  it  drops  to  the  floor 
of  the  cave,  and  drying  up  gradually,  forms,  in  like  manner, 
a  stalactite  rising  upwards  from  the  ground,  instead  of 
hanging  from  the  roof;  these  are  called,  for  the  sake  of 
distinction,  stalagmites. 

It  frequently  happens,  where  these  processes  are  unin- 
terrupted, that  a  stalactite  hanging  from  the  roof,  and  a 
stalagmite  formed  immediately  under  it  from  the  super- 
abundant water,  increase  till  they  unite,  and  thus  consti- 
tute a  natural  pillar,  apparently  supporting  the  roof  of  the 
grotto;  it  is  to  the  grotesque  forms  assumed  by  stalactites, 
and  these  natural  columns,  that  caverns  owe  the  interesting 
appearances,  described  in  such  glowing  colours  by  those 
who  witness  them  for  the  first  time. — Saturday  Magazine, 
No.  42. 


D.  Page  62. — WEYER'S  CAVE. — This  cave  is  situated  in 
a  ridge  of  limestone  hills,  running  parallel  to  the  Blue 
mountains.  A  narrow  and  rugged  fissure  leads  to  a  large 
cavern,  where  the  most  grotesque  figures,  formed  by  the 
percolation  of  water  through  beds  of  limestone,  present 
E  E 


418  APPENDIX. 

themselves,  while  the  eye,  glancing  onward,  watches  the 
dim  and  distant  glimmers  of  the  lights  of  the  guides — some 
in  the  recess  below,  and  others  in  the  galleries  above. 
Passing  from  these  recesses,  the  passage  conducts  to  a 
flight  of  steps  that  leads  into  a  large  cavern  of  irregular 
form,  and  of  great  beauty.  Its  dimensions  are  about  thirty 
feet  by  fifty.  Here  the  incrustations  hang  just  like  a  sheet 
of  water  that  has  been  frozen  as  it  fell ;  there  they  rise  into 
a  beautiful  stalactitic  pillar,  and  yonder  compose  an  ele- 
vated seat,  surrounded  by  sparry  pinnacles.  Beyond  this 
room  is  another,  more  irregular,  but  more  beautiful.  Be- 
sides having  sparry  ornaments  in  common  with  the  others, 
overhead  is  a  roof  of  the  most  admirable  and  singular 
formation.  It  is  entirely  covered  with  stalactites,  which 
are  suspended  from  it  like  inverted  pinnacles.  They  are 
of  the  finest  material,  and  are  most  beautifully  shaped  and 
embossed.  In  another  apartment,  an  immense  sheet  of 
transparent  stalactite  extends  from  the  roof  to  the  floor, 
which,  when  struck,  emits  deep  and  mellow  sounds,  like 
those  of  a  muffled  drum.  Farther  on  is  another  vaulted 
chamber,  which  is  one  hundred  feet  long,  thirty-six  wide, 
and  twenty-six  high.  Its  walls  are  filled  with  grotesque 
concretions.  The  effect  of  the  lights  placed  by  the  guides 
at  various  elevations,  and  leaving  hidden  more  than  they 
reveal,  is  extremely  fine.  At  the  extremity  of  another  range 
of  apartments,  a  magnificent  hall,  two  hundred  and  fifty  feet 
long,  and  thirty-three  feet  high,  suddenly  appears.  Here 
is  a  splendid  sheet  of  rock-work,  running  up  the  centre  of 
the  room,  and  giving  it  the  aspect  of  two  separate  and  noble 
galleries ;  this  partition  rises  twenty  feet  above  the  floor, 
and  leaves  the  fine  span  of  the  arched  roof  untouched. 
There  is  here  a  beautiful  concretion,  which  has  the  form 
and  drapery  of  a  gigantic  statue ;  and  the  whole  place  is 
filled  with  stalagmitical  masses  of  the  most  varied  and 
grotesque  character.  The  fine  perspective  of  this  room, 
four  times  the  length  of  an  ordinary  church,  and  the 
amazing  vaulted  roof  spreading  overhead,  without  any 
support  of  pillar  or  column,  produces  a  most  striking  effect. 
In  another  apartment,  which  has  an  altitude  of  fifty  feet, 
there  is  at  one  end  an  elevated  recess,  ornamented  with  a 
group  of  pendant  stalactites  of  unusual  size,  and  singular 
beauty.  They  are  as  large  as  the  pipes  of  a  full-sized 


APPENDIX.  419 

organ,  and  ranged  with  great  regularity ;  when  struck, 
they  emit  mellow  sounds  of  various  keys,  not  unlike  the 
tones  of  musical  glasses.  Other  cavities,  profusely  studded 
with  sparry  incrustations,  extend  through  the  limestone 
rock.  The  length  of  this  extraordinary  group  of  caverns 
is  not  less  than  one  thousand  six  hundred  feet. — Abridged 
from  "  A  Narrative  of  the  Visit  to  the  American  Churches" 
by  Drs.  Reed  and  Matheson. 


E.  Page  80. —  RECENT  FORMATION  OF  SANDSTONE, — 
"  A  sandstone  occurs  in  various  parts  of  the  northern 
coast  of  Cornwall,  which  affords  a  most  instructive  ex- 
ample of  a  recent  formation  ;  since  we  here  actually  detect 
Nature  at  work  in  converting  calcareous  sand  into  stone. 
A  very  considerable  portion  of  the  northern  coast  of 
Cornwall  is  covered  with  a  calcareous  sand,  consisting 
of  minute  particles  of  comminuted  shells,  which,  in  some 
places,  has*  accumulated  in  quantities  so  great,  as  to 
have  formed  hills  of  from  forty  to  sixty  feet  in  elevation. 
In  digging  into  these  sand  hills,  or  upon  the  occasional 
removal  of  some  part  of  them  by  the  winds,  the  remains 
of  houses  may  be  seen  :  and  in  some  places,  when  the 
churchyards  have  been  overwhelmed,  a  great  number  of 
human  bones  may  be  found.  The  sand  is  supposed  to 
have  been  originally  brought  from  the  sea  by  hurricanes, 
probably  at  a  remote  period.  At  the  present  moment,  the 
progress  of  its  incursion  is  arrested  by  the  growth  of  the 
arundo  arenacea.  The  sand  first  appears  in  a  slight  but 
increasing  state  of  aggregation  on  several  parts  of  the  shore 
in  the  Bay  of  St.  Ives;  but,  on  approaching  the  Gwythian 
river,  it  becomes  more  extensive  and  indurated.  On  the 
shore  opposite  Godrevy  Island,  an  immense  mass  of  it 
occurs,  of  more  than  a  hundred  feet  in  length,  and  from 
ten  to  twenty  in  depth,  containing  entire  shells  and  frag- 
ments of  clay-slate ;  it  is  singular  that  the  whole  mass 
assumes  a  striking  appearance  of  stratification.  In  some 
places,  it  appears  that  attempts  have  been  made  to  separate 
it,  probably  for  the  purpose  of  building,  for  several  old 
houses  in  Gwythian  are  built  of  it.  The  rocks  in  the 
vicinity  of  this  recent  formation  in  the  Bay  of  St.  Ives,  are 
E  E  2 


420  APPENDIX. 

greenstone  and  clay  slate,  alternating  with  each  other. 
The  clay  slate  is  in  a  state  of  rapid  decomposition,  in  con- 
sequence of  which  large  masses  of  the  hornblende  rock 
have  fallen  in  various  directions,  and  given  a  singular  cha- 
racter of  picturesque  rudeness  to  the  scene.  This  is 
remarkable  in  the  rocks  which  constitute  Godrevy  Island. 
It  is  around  the  promontory  of  New  Kaye,  that  the  most 
extensive  formation  of  sandstone  takes  place.  Here  it 
may  be  seen  in  different  stages  of  induration,  from  a  state 
in  which  it  is  too  friable  to  be  detached  from  the  rock  upon 
which  it  reposes,  to  a  hardness  so  considerable  that  it 
requires  a  very  violent  blow  from  a  sledge  to  break  it. 
Buildings  are  here  constructed  of  it ;  the  church  of  Cran- 
stock  is  entirely  built  with  it ;  and  it  is  also  employed  for 
various  articles  of  domestic  and  agricultural  uses.  The 
geologist  who  has  previously  examined  the  celebrated  spe- 
cimen from  Guadaloupe,  will  be  struck  with  the  great 
analogy  which  it  bears  to  this  formation.  Suspecting 
that  masses  might  be  found  containing  human  bones, 
if  a  diligent  search  were  made  in  the  vicinity  of  those 
cemeteries  which  have  been  overwhelmed,  I  made  some 
investigations  in  those  spots,  but,  I  regret  to  add,  without 
success.  The  rocks  upon  which  the  sandstone  reposes,  are 
alternations  of  clay  slate,  and  slaty  limestone.  The  in- 
clination of  the  beds  is  SS.W.,  and  at  an  angle  of  40°. 
Upon  a  plane  formed  by  the  edges  of  these  strata,  lies  a 
horizontal  bed  of  rounded  pebbles,  cemented  together  by 
the  sandstone  which  is  deposited  immediately  above  them, 
forming  a  bed  of  from  ten  to  twelve  feet  in  thickness,  and 
containing  fragments  of  slate,  and  entire  shells;  and  exhi- 
biting the  same  appearance  of  stratification  as  that  noticed 
in  St.  Ives  Bay.  Above  this  sandstone  lie  immense  heaps 
of  drifted  sand.  But  it  is  on  the  western  side  of  the  pro- 
montory of  New  Kaye,  in  Fishel  Bay,  that  the  geologist 
will  be  most  struck  with  this  formation ;  for  here  no  other 
rock  is  in  sight.  The  cliffs,  which  are  high,  and  extend 
for  several  miles,  are  entirely  composed  of  it ;  they  are 
occasionally  intersected  by  veins  and  dykes  of  breccia. 
In  the  cavities,  calcareous  stalactites  of  rude  appearance, 
opaque,  and  of  a  grey  colour,  hang  suspended.  The  beach 
is  covered  with  disjointed  fragments,  which  have  been 
detached  from  the  cliffs  above,  many  of  which  weigh  two 


APPENDIX.  421 

or  three  tons." — From  the  Transactions  of  the  Royal  Geo- 
logical Society  of  Cornwall,  by  Dr.  Paris. 


F.  Page  95. — LITHODOMI,  or  BORING  MOLLUSCA;  which 
have  the  power  of  perforating  rocks. — Every  one  who  has 
walked  by  the  sea-side  must  have  observed  the  blocks  and 
masses  of  the  chalk  rocks  full  of  perforations ;  and  if  his 
curiosity  have  induced  him  to  examine  these  with  attention, 
he  will  have  perceived  that  though  many  of  the  6avities 
are  empty,  some  of  them  contain  the  shelly  remains  of  the 
animals  which  once  inhabited  them.  The  power  possessed 
by  creatures  so  delicate,  and  with  such  fragile  coverings, 
of  excavating  the  solid  rock,  has  naturally  excited  much 
speculation  as  to  the  mode  by  which  the  perforations  are 
effected ;  and  it  is  now  generally  admitted,  that  it  is  not 
by  mechanical  power  only  that  the  feeble  inhabitants  of 
the  boring  shells  are  able  to  form  themselves  a  secure 
asylum  in  the  rock,  but  by  the  secretion  of  a  liquid  which 
acts  chemically  on  the  stone,  softens  it,  and  renders  it 
capable  of  being  removed  with  facility.  In  a  late  volume 
of  the  Philosophical  Transactions,  there  is  an  interesting 
paper  on  the  economy  of  molluscous  animals,  by  Mr.  Gray, 
which  throws  much  light  on  the  subject.  It  appears  that, 
although  teredines,  pholades,  and  other  boring  shells,  are 
covered  with  short  spines  and  striae,  by  means  of  which 
they  were  supposed  capable  of  rasping  stones,  yet  other 
mollusca  which  inhabit  stony  cavities  are  perfectly  smooth. 
On  the  shore,  near  Kemptown,  a  pholas,  which  has  a 
rasping  apparatus,  and  a  venus,  wholly  destitute  of  a  rugous 
surface,  may  be  seen  in  cavities  of  the  chalk.  Shells 
of  this  kind  have  not  been  observed  to  bore  into  any  other 
substances  (wood  excepted)  than  shells,  marl,  chalk,  lime- 
stone, and  sandstone,  consolidated  by  calcareous  cement. 
Granite  appears  to  resist  all  the  dissolving  powers  of  the 
mollusca.  Thus,  in  the  Plymouth  Breakwater,  in  which 
limestone  and  granite  are  employed  and  placed  side  by 
side,  the  patella,  or  limpets,  form  their  r.ounded  holes  in 
the  former,  while  they  do  not  in  the  slightest  degree  alter 
the  surface  of  the  latter,  except  by  clearing  off  from  it  any 
adherent  calcareous  substance. 


422  APPENDIX. 

G.  Page  96. — OBSERVATIONS  ON  THE  TEMPLE  OF  SERAPIS, 
AT  PUZZUOLI,  NEAR  NAPLES;  in  a  Letter  to  W.H.Fitton, 
M.D.,  from  Charles  Babbage,  Esq.  —  This  paper  com- 
mences with  a  general  description  of  the  present  state  of 
the  Temple  of  Serapis,  and  gives  the  measurement  of  the 
three  marble  columns  which  remain  standing,  and  which, 
from  the  height  of  eleven  feet  to  that  of  nineteen,  are  per- 
forated on  all  sides  by  the  modiola  lithophaga  (of  Lamarck)  ; 
the  shells  of  that  animal  remaining  in  the  holes  formed  by 
them  in  the  columns.  A  description  follows  of  the  present 
state  of  twenty-seven  portions  of  columns,  and  other  frag- 
ments of  marble,  and  also  of  the  several  incrustations 
formed  on  the  walls  and  columns  of  the  temple. 

From  these  and  other  data,  Mr.  Babbage  concludes  : — 

1.  That  the  temple  was  originally  built  at,  or  nearly  at 
the  level  of  the  sea,  for  the  convenience  of  sea-baths,  as 
well  as  for  the  use  of  the  hot  spring  which  still  exists  on 
the  land  side  of  the  temple. 

2.  That,  at  a  subsequent  period,  the  ground  on  which 
the  temple  stood,  subsided  slowly  and  gradually ;  the  salt 
water,  entering  through  a  channel  which  connected  the 
temple  with  the  sea,  or  by  infiltration  through  the  sand, 
mixed  itself  with  the  water  of  the  hot  spring  containing 
carbonate  of  lime,  and  formed  a  lake  of  brackish  water  in 
the  area  of  the  temple,  which,  as  the  land  subsided,  became 
deeper,  and  formed  a  dark  incrustation. 

The  proofs  are,  that  sea-water  alone  does  not  produce  a 
similar  incrustation ;  and  that  the  water  of  the  hot  spring 
alone  produces  an  incrustation  of  a  different  kind;  also, 
that  serpulse  are  found  adhering  to  this  dark  incrustation  ; 
and  that  there  are  lines  of  water-level  at  various  heights 
from  2.9  feet  to  4.6  feet. 

3.  The  area  of  the  temple  was  now  filled  up  to  the  height 
of  about  seven  feet  with  ashes,  tufa,  or  sand,  which  stopped 
up  the  channel  by  which  sea-water  had  been   admitted. 
The  waters  of  the  hot  spring  thus  confined,  converted  the 
area  of  the  temple  into  a  lake,  from  which  an  incrustation 
of  carbonate  of  lime  was  deposited  on  the  columns  and  walls. 
The  proofs  are,  that  the  lower  boundary  of  this  incrustation 
is  irregular ;  whilst  the  upper  is  a  line  of  water-level,  and 
that  there  are  many  such  lines  at  different  heights;— that 
salt  water  has  not  been  found  to  produce  a  similar  incrus- 


APPENDIX.  423 

tation ; — that  the  water  of  the  Piscina  Mirabile,  which  is 
distant  from  the  sea,  but  in  this  immediate  neighbourhood, 
produces,  according  to  an  examination  by  Dr.  Faraday,  a 
deposit  almost  precisely  similar ; — that  no  remains  of  ser- 
pulae,  or  other  marine  animals,  are  found  adhering  to  it. 

4.  The  temple  continuing  to  subside,  its  area  was  again 
partially  filled  with  solid  materials ;  and  at  this  period  was 
subjected  to  a  violent  incursion  of  the  sea.     The  hot- water 
lake  was  filled  up,  and  a  new  bottom  produced,  entirely 
covering  the  former,  and  concealing  also  the  incrustation 
of  carbonate  of  lime. 

The  proofs  are,  that  the  remaining  walls  of  the  temple 
are  highest  on  the  inland  side,  and  decrease  in  height 
towards  the  sea-side,  where  they  are  lowest ; — that  the 
lower  boundary  of  the  space  perforated  by  the  marine 
lithophagi  is,  on  different  columns,  at  different  distances 
beneath  the  uppermost,  or  water-level  line; — that  several 
fragments  of  columns  are  perforated  at  the  ends. 

5.  The  land  continuing  to  subside,  the   accumulations 
at  the  bottom  of  the  temple  were  submerged,  and  modiolae 
attaching   themselves  to  the  columns  and  fragments  of 
marble,  pierced  them  in  all  directions.     The  subsidence 
continued  until  the  pavement  of  the  temple  was  at  least 
nineteen  feet  below  the  level  of  the  sea. 

The  proofs  are  derived  from  the  condition  of  the  columns 
and  fragments. 

6.  The  ground  on  which  the  temple  stood,  appears  now 
to  have  been  stationary  for  some  time,  but  it  then  began  to 
rise.     A  fresh  deposition  of  tufa,  or  of  sand,  was  lodged, 
for  the  third  time,  within  its  area,  leaving  only  the  upper 
part  of  three  large  columns  visible  above  it. 

Whether  this  took  place  before  or  subsequently  to  the 
rise  of  the  temple  to  its  present  level,  does  not  appear ;  but 
the  pavement  of  the  area  is  at  present  level  with  the  waters 
of  the  Mediterranean. 

The  author  then  states  several  facts,  which  prove  that 
considerable  alterations  in  the  relative  level  of  the  land 
and  sea  have  taken  place  in  the  immediate  vicinity.  An 
ancient  sea-beach  exists  near  Monte  Nuovo,  two  feet  above 
the  present  beach  of  the  Mediterranean.  The  broken 
columns  of  the  Temples  of  the  Nymphs  and  of  Neptune, 
remain  at  present  standing  in  the  sea.  A  line  of  perfora- 


424 


APPENDIX. 


tions  of  modiolae,  and  other  indications  of  a  water-level 
four  feet  above  the  present  sea,  are  observable  on  the  sixth 
pier  of  the  bridge  of  Caligula ;  and  again  on  the  twelfth 
pier,  at  the  height  of  ten  feet.  A  line  of  perforations  by 
modiolae  is  visible  in  a  cliff  opposite  the  island  of  Nisida, 
thirty-two  feet  above  the  present  level  of  the  Mediter- 
ranean.— Abstract  of  the  Proceedings  of  the  Geological 
Society  ;  March,  1834. 


H.  Page  325. —  Mr.  Reade's  recent  observations  on 
fossil  infusoria  are  embodied  in  Lecture  VI.  See  also 
Appendix  N  and  O. 


I.  Page  328. — AGASSIZ'S  CLASSIFICATION  OF  FISHES. 


TAB.  84. — SCALES  OF  THE  FOUR  ORDERS  OF  FISHES,  AS  DETERMIKED 
BY  M.  AGASSIZ. 

1.  Scale  of  a  Ganoid  order — of  Lepidotus. 

2.  „         Placoid  order — of  Ray. 

3.  ,,         Cycloid  order — of  Salmon. 

4.  „        Ctenoid  order — of  Beryx. 


APPENDIX.  425 

K.  Page  339. — A  TABULAR  ARRANGEMENT  OF  THE  FOSSIL 
FISHES  OF  THE  CHALK  FORMATION  OF  THE  SOUTH-EAST  OF 
ENGLAND,  COLLECTED  BY  GIDEON  MANTELL,  LL.D.  F.R.S.  ; 
IN  THE  MANTELLIAN  MUSEUM  AT  BRIGHTON.* 

(From  "  Recherches  sur  les  Poissons  Fossiles"  by  M.  Agassiz.) 

"  Tout  le  monde  sait  que  le  Musfee  de  M.  le  Dr.  Mantell  &  Brighton  est  une  collection 
classique  pour  la  craie,  et  la  formation  Veldienne.  Les  soins  minutieux  que  M.  Mantell 
a  donnes  tlepuit  bicn  des  annees  4  ces  fossiles,  les  ont  rendus  plus  parlaits  que  tons 
ceux  des  autres  musfees  ;  car  souvent  il  est  parvenu  ft  les  detacher  entierement  de  la 
roche  dans  laquelle  ils  se  trouvaient;  ou  du  moins  a  les  produire  en  relief,  en  dfetachant 
toutes  les  matieres  solides  qui  recouvraient  les  parties  les  mieux  conservees  de 
l'anhnal." 

ORDER  I. — The  Placoidians,  (from  7rXa£,  a  broad  plate.) 
The  skin,  covered  irregularly  with  enamelled  plates,  some- 
times of  a  large  size,  but  frequently  in  the  form  of  small 
points,  as  in  the  shagreen  on  the  skin  of  sharks,  and  the 
tubercles  on  the  integuments  of  rays.  Tab.  84,  fig.  2. 

PTTCHODUS  latissimus.  Mantell's  South  Down  Fossils.  Tab.  xxxii.  fig.  19. 
Agassiz,  Poiss.  Foss.  Vol.  iii.  tab.  25. 

polygyrus.    Ibid.    Tab.  xxxii.  figs.  23,  24. 

mammillaris.     Ibid.    Tab.  xxxii.  figs.  18,  20,  25,  29, 

decurrens.     Tab.  58,  fig.  6,  page  329. 

altior.    South  Down  Fossils.    Tab.  xxxii.  figs.  17,  21,  27. 

Teeth,  and  perhaps  vertebrae,  of  the  above  species,  and  a 
few  examples  of  their  dorsal  defences,  (Ichthyodorulites  of 
Dr.  Buckland,)  are  the  only  remains  hitherto  discovered. 
(Agass.  Poiss.  Foss.  Vol.  iii.  tab.  10*,  10V)  The  teeth 
were  referred  to  fishes  of  the  genus  Diodon,  by  previous 
authors,  and  the  defences  were  called  radii,  or  fin-bones  of 
balistes,  and  siluri. 

Teeth  of  a  new  species  of  PtycJiodus  have  been  dis- 
covered in  the  sand  of  New  Jersey,  United  States,  by  Dr. 
Morton. — (Mortons  Synopsis,  PI.  18,  fig.  1,  2.)  I  have 
named  it  Ptychodus  Mortoni. 

PTYCHODUS, — spec,  undetermined.  Dorsal  defences,  and  a  beautiful  ex- 
ample of  a  fin,  are  represented  in  the  Fossils  of  the  South 
Downs.  Tab.  xxxiv.  fig.  8.  Tab.xxxix.andTab.xl.  fig.3. 

GAL-EVSpristodontus.  Tab.  58,  fig.  3.  South  Down  Fossils.  Tab.  xxxii. 
figs.  12  to  16.  Agass.  Poiss.  Foss.  Vol.  iii.  tab.  xxvi. 
fig.  14. 

NOTIDANUS  microdon.  Tab.  58,  fig.  1,  page  329.  Agass.  Tab.  xxxii. 
fig.  22. 

LAMNA  appendiculata.  Tab.  58.  fig.  4,  page  329.  Agass.  Tab.  xxxii. 
figs.  2,  3,  5,  6.  9. 

acuminata.    Agass.    Tab.  xxxii.  fig.  1. 

*  Now  in  the  British  Museum. 


426  APPENDIX. 

LAMNA  Mantellii.    Tab.  58,  fig.  2,  page  329.   Agass.    Tab.  xxxii.  figs.  4, 
7,  8,  10. 

crassissima.    Not  figured. 

ODONTAPSIS  raphiodon.     Not  figured. 

SPIN  AX  major.    Agass.  Poiss.  Foss.    Vol.  iii.  tab.  10,  figs.  8,  14. 
PSAMMODUS  asper.     Poiss.  Foss.    Vol.  iii.  tab.  10,  figs.  1,  3. 
ACRODUS  transversus.     Poiss.  Foss.    Vol.  iii.  tab.  10,  figs.  4,  5. 
GYRODUS  angustus.     Poiss.  Foss.    Vol.  ii.  tab.  66a,  figs.  14,  15. 

The  above  order  of  fishes  is  represented  by  five  genera, 
of  which  one,  containing  twelve  species,  is  extinct.  The 
fishes  of  the  genera  Ptychodus.  Galeus,  and  Lamna,  are 
very  widely  distributed. 

ORDER  II. — The  Ganoidians, — (yavos,  splendour,  from 
the  brilliant  surface  of  their  enamel.)  These  are  charac- 
terised by  angular  scales,  formed  of  horny  or  bony  plates, 
protected  by  a  thick  layer  of  enamel.  Tab.  84,  fig.  1. 

MACROPOMA  Mantellii.  Tab.  61,  page  334.  Length  24  inches.  South 
Down  Fossils.  Tab.  xxxvii.  and  xxxviii.  Agass. 
Poiss.  Foss.  Vol.  v.  tab.  60b,  fig.  2. 

Coprolites  of :  South  Down  Fossils.  Tab.  ix. 

figs.  5,  11.  Agass.  Poiss.  Foss.  Vol.  ii.  tab.  65. 

The  Macropoma  is  perhaps  the  most  remarkable  of  all 
the  fossil  fishes ;  in  most  examples  the  membranes  of  the 
stomach  are  preserved. 

SpHffiRODUS  mammillarts.     Not  figured.    From  Clayton  chalk-pit. 
DERCETIS  elongatus.   Tab.  62,  page  335.   Length  16  inches.   South  Down 

Fossils.  Tab.  xxxiv.figs.  10, 11.  Tab.xl.  fig.  2.  Agass. 

Poiss.  Foss.  Vol.  ii.  tab.  66a,  figs.  1  to  8. 

The  above  order  comprehends  three  extinct  genera,  with 
three  species.  Another  species  of  Dercetis  has  been  found 
in  the  chalk  of  Westphalia. 

ORDER  III. — The  Cteno'idians,  (KTCIS,  a  comb.)  The 
scales  of  this  order  are  pectinated  on  their  posterior  margin, 
like  the  teeth  of  a  comb,  and  are  composed  of  laminae  of 
horn  or  bone,  but  have  no  enamel.  Tab.  84,  fig.  4. 

BERYX  Lewesiensis.    (B.  ornatus  of  Agassiz.;  Tab.  64,  page  337.  Length 

12  inches.     South  Down  Fossils.     Tab.  xxxiv.  fig.  6. 

Tab.  xxxv.  Tab.  xxxvi.    Agass.  Poiss.  Foss.  Vol.  iv. 

tab.  14a. 
radians.     Tab.  63,  page  336.     Length  7  inches.     History  of  the 

County  of  Sussex.  Vol.  ii.  Part  ii.  p.  15;  fig.  22.  Agass. 

Poiss.  Foss.  Vol.  iv.  tab.  14b,  fig.'7.  , 
microcephalus.    Agass.  Poiss.  Foss.  Vol.  iv.  tab.  4c,  figs.  7  to  9. 


APPENDIX.  127 

There  are  other  species  of  Beryx  in  the  chalk  of  Bohemia 
and  Westphalia  ;  and  genera  nearly  related  to  Beryx,  in 
the  schist  of  Glaris.  In  England  this  order  contains  but 
three  species  of  a  genus,  of  which  we  know  but  one  living 
species. 

ORDER  IV. — The  Cydoidiam,  (KVK\OS,  a  circle.)  The 
scales  smooth,  with  a  simple  margin,  composed  of  laminae 
of  horn  or  bone  without  enamel.  Tab.  84,  fig.  3. 

OSMEROIDES  Mantellii.  (Salmo  ?  Lewesiensis  of  Mantell.)  Tab.  60, 
page  333.  Length  12  inches.  South  Down  Fossils. 
Tab.  xxx.  fig.  12.  Tab.  xxxiv.  fig.  3.  Tab.  xl.  fig.  1. 
Agass.  Poiss.  Foss.  Vol.  v.  tab.  60o. 

To  the  above  species  belong  the  remarkable  uncompressed 
specimens  in  my  Museum. 

OSMEROIDES  Lewesiensis.  Agass.  Poiss.  Foss.  Vol.  v.  tab.  60C.  (Salmo? 
Lewesiensis  of  Mantell.)  This  species  is  more  elon- 
gated than  0.  Mantellii,  and  the  number  of  rays  in 
the  dorsal  fin  is  greater. 

granulatus.  History  of  Lewes.  Vol.  i.  plate  xxix.  fig.  13. 

The  bones  of  the  head,  with  the  jaws  and  teeth,  have 
alone  been  discovered.  Agass.  Poiss.  Foss. 

ENCHODUS  halocyon.  South  Down  Fossils.  Tab.  xxxiii.  figs.  2,  3,  4. 
Tab.  xliv.  figs.  1,  2.  Agass.  Poiss.  Foss.  Vol.  v.  tab.  25. 
figs.  11  to  6. 

SAUROCEPHALUS  lanciformis.  (Harlan.)  South  Down  Fossils.  Tab. 
xxxiii.  figs.  7,  G.  Trans.  Geol.  Soc.  of  Pennsylvania, 
Vol.  i.  p.  83.  Agass.  Poiss.  Foss.  Vol.  v.  tab.  25,  figs. 
21  to  2y. 

SAURODON  Leanus.  (Hays.)  Trans.  American  Philos.  Society,  vol.  for 
1830,  plate  16.  Agass.  Poiss.  Foss.  Vol.  v.  tab.  25, 
figs.  17  to  20. 

HYPSODON  Lewesiensis.  South  Down  Fossils.  Tab.  xxxiii.  fig.  8.  Tab. 
xlii.  figs.  1  to  5.  Agass.  Poiss.  Foss.  Vol.  v.  tab.  25». 

From  the  resemblance  of  the  teeth  of  this  fish,  to  those 
of  reptiles,  it  was  supposed  that  the  original  belonged  to 
an  extinct  genus  of  saurians;  but  in  1833,  a  considerable 
portion  of  the  head,  with  the  maxilla?,  many  vertebrae,  &c., 
were  discovered  in  a  block  of  chalk,  near  Lewes,  and  the 
true  characters  of  this  remarkable  ichthyolite  determined. 

*#*  The  following  fishes  have  been  named  by  M.  Agassiz, 
since  the  above  table  was  constructed. 

ACROGNATHXJS  boop*.  Tab.  GO,  page  333.  Natural  size.  Agass.  Poiss. 
Foss.  Vol.  iii.  tab.  60a,  figs.  1,  4.  An  unique  specimen 
from  Southerham  quarry,  near  Lewes. 


428  APPENDIX. 

AULOI.EPIS  typus.  Tab.  61,  page  334.  Length  6  inches.  An  unique 
specimen,  from  Clayton  chalk-pit,  Sussex.  One 
nearly  perfect  example  has  alone  been  found.  Poiss. 
Foss.  Vol.  iii.  tab.  60,  figs.  5,  8. 

BELONOSTOMUS  cinctus.  Agass.  Poiss.  Foss.  Vol.  ii.  tab.  66a,  figs.  10  to  13. 

CHIMERA  Agassizii.  Agass.  Poiss.  Foss.  Vol.  iii.  pi.  40,  figs.  3,  5.  (De- 
termined by  Dr.  Buckland.)  The  beaks  or  mandibles 
have  alone  been  discovered. 

Mantellii.  Tab.  59,  page  330.  Agass.  Poiss.  Foss.  Vol.  iii. 

pi.  40,  figs.  1,  2.  Two  mandibles  were  found,  many 
years  since,  in  a  block  of  chalk,  near  Lewes.  This 
species  also  occurs  in  the  Shanklin  sand  of  Kent.  A 
beak  has  been  found  by  Mr.  W.  H.  Bensted  in  the 
iguanodon  quarry,  near  Maidstone. 

TETRAPTERUS  minor.  Lewes.  Agass.  Poiss.  Foss.  Vol.  iii.  tab.  60, 
figs.  1,  4. 

CATCRUS  similis.    Agass.  Poiss.  Foss.   Vol.  ii.  tab.  66a,  fig.  9. 

ACROTEMNUS  faba.     Poiss.  Foss.   Vol.  ii.  tab.  66a,  figs.  16,  18. 


L.  Page  395. — MAIDSTONE  IGUANODON. — This  specimen 
was  purchased  of  Mr.  Bensted  in  its  broken  state,  and 
presented  to  Dr.  Mantell  by  the  following  gentlemen  of 
Brighton,  the  proposition  originating  with  the  two  whose 
names  stand  first  on  the  list,  viz. — Horace  Smith,  Moses 
Ricardo,  Thomas  Attree,  George  Basevi,  Thomas  Bodley, 
R.  Heaviside,  E.  Lindo,  J.  J.  Masquerier,  W.  Tenant,  and 
T.  Sarel,  Esqrs.;  Drs.  Hall  and  Price;  Revds.  J.  S.  M. 
Anderson,  Thomas  Rooper,  H.  M.  Wagner;  and  Sir 
Richard  Hunter. 


END    OF    VOL.    I. 


RICHARD    CLAY,    PRINTER,    BREAD   STREET   HILL. 


DESCRIPTION  OF  THE  FRONTISPIECE. 


The  Country  of  the  Iguanodon,  restored  from  the  Geological  Discoveries  of 
the  Author.    By  JOHN  MARTIN,  Esq.  K.L. 


The  mode  of  induction  by  which  the  geologist  and  comparative 
anatomist  are  enabled  to  ascertain  the  form  and  structure  of  animals 
and  plants  which  no  longer  exist  on  the  face  of  the  earth,  and  even  the 
nature  of  the  countries  which  they  inhabited,  are  explained  in  the  fol- 
lowing pages.  The  researches  of  the  Author  in  the  wealden  formation 
(p.  344)  of  the  south-east  of  England,  furnished  the  materials  from  which 
the  eminent  painter  of  "BELSHAZZAR'S  FEAST,"  composed  the  striking 
picture  that  forms  so  splendid  an  embellishment  to  this  Work. 

The  data  upon  which  the  restorations  are  founded  are  described  in  the 
Fourth  Lecture  (see  p.  404).  The  picture  represents  a  country  clothed 
with  a  tropical  vegetation,  peopled  by  reptiles  of  colossal  magnitude,  and 
traversed  by  a  river,  which  is  seen  to  empty  itself  into  the  sea,  in  the 
distance.  Oolitic  rocks  (p.  361)  form  the  heights  and  cliffs  with  which  the 
landscape  is  diversified.  The  vegetation  consists  of  the  trees  and  plants 
whose  fossil  remains  have  been  discovered  in  Tilgate  Forest  (p.  369) ; 
namely,  palms,  arborescent  ferns,  clathrariae,  and  coniferous  tree ;  while 
the  lesser  plants,  as  the  cycadeae,  (p.  365)  and  ferns  (pp.  369—371),  are 
distributed  over  the  foreground. 

The  reptiles  comprise  the  iguanodon  (p.  389),  hylaeosaurus  (p.  401), 
megalosaurus  (p.  389),  crocodiles  (p.  385),  and  turtles  (p.  384).  An 
iguanodon  attacked  by  a  megalosaurus  and  crocodile,  constitutes  the 
principal  group ;  in  the  middle  distance  an  iguanodon  and  hylaeosaurus 
are  preparing  for  an  encounter;  a  solitary  pterodactyle,  or  flying 
reptile  (p.  403),  with  its  wings  partly  expanded,  forms  a  conspicuous 
object  in  the  foreground ;  while  turtles  are  seen  crawling  on  the  banks  of 
the  river.  Ammonites  and  other  shells  of  the  Portland  oolite,  which  is 
the  foundation  rock  of  the  country,  are  strewn  on  the  shore.  Wading 
birds  allied  to  the  heron  (p.  403),  should  have  been  introduced  to  render 
the  fauna  of  the  iguanodon  country  complete. 

The  vigour  and  beauty  of  this  successful  conception  of  the  distinguished 
artist  are  equalled  by  the  fidelity  of  its  details. 


FOSSIL   CROCODILE    DISCOVERED  AT    SWANAGE 


DESCRIPTION  OF  PLATE  I. 


Remains  of  a  Fossil  Crocodile  discovered  at  Swanage,  by  ROBERT 
TROTTER,  Esq.  F.G.S.  of  Borda  Hill,  near  Cuckfield. 

Described  pp.  387-389. 


1.  The  left  side  of  the  lower  jaw,  with  two  teeth  remaining  in  their 
natural  position:  fig.  10,  PI. III.  represents  one  of  these  teeth 
on  a  larger  scale. 

2,  2.  Detached  vertebrae  of  the  back  and  tail,  showing  the  transverse 

and  dorsal  processes. 

3,  3.  Dermal,  or  skin  bones  :   in  the  living  animal  these  are  disposed 

in  parallel  rows  along  the  spinal  column,  like  a  ridge  of  roof- 
tiles,  and  are  designed  to  support  the  large  scales. 

4,  4.  Ribs,  more  or  less  broken. 

5.  Two  chevron  bones :  these  are  inferior  spinous  processes  articu- 
lated to  the  vertebrae  of  the  tail.  In  a  specimen  of  caudal  ver- 
tebrae of  the  iguanodon,  (PI.  III.  fig.  8, 6.)  three  processes  of  this 
kind,  but  differing  in  form  from  those  before  us,  are  seen  lying 
beneath  the  vertebras. 
6,  7,  8.  Bones  of  the  pelvis. 

6.  One  of  the  bones  of  the  pelvis,  detached;    the  corresponding 

bone  is  seen  near  the  following. 

7.  7.  The  bones  of  the  ischium. 

8.  The  remaining  bones  of  the  pelvis,  attached  to  each  other  in 

their  natural  position. 

Numerous  scales  and  teeth  of  a  fresh -water  fish,  (lepidotus  minor,) 
peculiar  to  the  Purbeck  strata,  are  imbedded  in  the  stone. 


1GUANOPON     DISCOVERED     NEAR     MAIDSTONE 
t;  FtfJ-.  l     Sut. 


DESCRIPTION  OF  PLATE  II. 


The  Remains  of  the  Iguanodon  discovered  by  Mr.  W.  H.  Bensted,  in  a 
Quarry  of  Kentish  Rag,  near  Maidstonc. 

Described  pp.  394—397. 


1,  2.  The  right  and  left  thigh-bone,  or  femur. 

3.  A  leg-bone,  or  tibia. 

4,  4,  4.  Bones  of  the  toes  (metatarsal  and  phalangeal)  of  the  hind  feet. 
5,  5.  Two  unguical,  or  claw-bones  of  the  hind-foot. 

6.  Two  metacarpal,  or  finger  bones  of  the  fore-foot. 

7.  One  of  the  bones  (radius)  of  the  fore-arm. 

8'  8,  8.  Vertebrae  of  the  back  and  tail :  in  the  upper  part  of  the  specimen 

a  series  of  eight  vertebrae  remains. 
9, 9,  9.  Ribs :  some  nearly  entire,  others  broken. 

10,  10.  Two  clavicles,  or  collar-bones. 

11,  11.  Two  bones  of  the  pelvis  (ossa  ilia). 

12.  A  chevron-bone,  or  inferior  spinous  process  of  the  tail. 


III 


REMAINS    OF  REPTILES  FROM  TILGATE   FGRFST. 


DESCRIPTION  OF  PLATE  III. 


Remains  of  Reptiles  from  the  strata  of  Tilgate  Forest. 


1 .  One  of  the  claw-bones  of  the  fore-foot  of  the  iguanodon.    See  p.  397. 

2.  One  of  the  claw-bones  of  the  hind-foot  of  the  Maidstone  iguanodon. 

See  p.  397. 

3.  Perfect  tooth  of  the  iguanodon,  one-third  the  natural  size.  See  p.  390. 

4.  Inner  surface  of  a  tooth  of  an  unknown  reptile.     See  p.  403. 

5.  Horn  of  the  iguanodon.     See  p.  400. 

6.  Tooth  of  the  iguanodon ;    the  crown  slightly  worn  by  use,  and  the 

fang  absorbed  from  pressure  of  the  new  tooth ;  half  the  natural 
size.  See  p.  390. 

7.  Tooth  of  the  iguanodon,  much  worn ;  the  serrated  edges  being  entirely 

obliterated  ;  half  the  natural  size.  This  is  the  individual  specimen 
which  M.  Cuvier  mistook  for  an  incisor  tooth  of  the  rhinoceros, 
until  a  series  of  specimens  was  obtained,  showing  a  gradual 
transition  from  the  perfect  to  the  worn  tooth. 

8.  Six  vertebrae  of  the  tail  of  an  iguanodon,  articulated  to  each  other, 

having  their  spinous  (a)  and  transverse  processes  remaining;  and 
three  chevron-bones  (b  b)  imbedded  in  the  stone  near  the  vertebras. 
From  Cuckfield,  by  R.  Trotter,  Esq.  See  p.  399. 

9.  Tooth  of  the  megalosaurus,  one-third  the  natural  size.  9*.  Magnified 

view  of  the  serrated  edge  ot  the  tooth.     See  p.  389. 

10.  Tooth  of  the  Swanage  crocodile.     See  p.  388. 

11.  The  right  femur,  or  thigh-bone,  of  an  iguanodon,  imbedded  in  lime- 

stone ;  from  Tilgate  Forest  (pp.  395—398).  The  original  was 
3  feet  8  inches  in  length,  a,  the  large  process  (trochanter  major),  on 
the  upper  and  outer  part  of  the  bone  ;  b,  the  inner  process  (tro- 
chanter minor),  for  the  attachment  of  adductor  muscles,  by  which 
the  limbs  were  drawn  towards  each  other ;  c,  the  inner  condyle ; 
d,  the  groove  in  front  of  the  condyles,  for  the  passage  of  a  tendon 
to  be  inserted  into  the  leg-bone. 


DESCRIPTION  OF  PLATE  IV. 


Remains  of  the  Hylceosaurus,  discovered  in  Tilgate  Forest. 

Described  pp.  401,402. 
(Size  of  the  original  specimen,  four  and  a  half  feet  in  length.) 


This  plate  represents  the  extraordinary  and  highly  interesting  fossil 
discovered  in  Tilgate  Forest,  by  the  Author,  in  the  summer  of  1832.  The 
specimen  exhibits  the  anterior  or  upper  portion  of  the  skeleton  of  an 
extinct  reptile,  the  hyl&osaurus,  or  fossil  lizard  of  the  weald. 

1.  Vertebrae  of  the  neck,  or  cervical. 

2.  Vertebrae  of  the  back,  or  dorsal. 

3.  Ribs,  for  the  most  part  perfect,  and  but  little  removed  from  their 

articulation  with  the  vertebrae. 
4,  4.  Angular  or  spinous  processes. 

5.  Three  very  large  spinous  or  angular  processes  ;  each  15  inches  in 
length. 

6,  6.  Two  coracoid  bones  (belonging  to  the  chest). 

7,  7.  The  two  omoplates,  or  scapulae. 


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